Journal of Nanomaterials
Volume 2018 (2018), Article ID 6862710, 9 pages
https://doi.org/10.1155/2018/6862710

Review Article

IR and UV/VIS Spectroscopic Characterization of the Higher Fullerene C₇₆-D₂ for Its Quantitative and Qualitative Determination

Tamara Jovanović,¹ Djuro Koruga,¹ Aleksandra Mitrović,¹ Dragomir Stamenković,¹ and Gordana Dević²

¹Department of Biomedical Engineering, Faculty of Mechanical Engineering, University of Belgrade, Kraljice Marije 16, 11120 Belgrade, Serbia
²Department of Chemistry, Institute of Chemistry, Technology and Metallurgy, University of Belgrade, Nemanjina 12, 11000 Belgrade, Serbia

Correspondence should be addressed to Tamara Jovanović; tamara.jovanovic@sbb.rs

Received 29 March 2018; Accepted 21 June 2018; Published 23 September 2018

Academic Editor: Paulo Cesar Morais

Copyright © 2018 Tamara Jovanović et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract.

The only stable isomer of the higher fullerene C₇₆ of D₂ symmetry was isolated from carbon soot by the new and advanced extraction and chromatographic methods and processes. Characterization of the isolated C₇₆-D₂ was performed by the IR(KBr) and UV/VIS method in the absorption mode. All of the experimentally observed infrared and electronic absorption bands are in excellent agreement with the theoretical calculations for this fullerene. The molar absorptivity and the integrated molar absorptivity of the observed entire new series of various characteristic, both deconvoluted and convoluted IR absorption bands of the C₇₆-D₂ isomer, in different integration ranges were determined. In addition, the molar extinction coefficients of its UV/VIS absorption bands were determined. The obtained novel IR and UV/VIS spectroscopic parameters are significant for the quantitative assessment of C₇₆-D₂. All the presented data are important both for its qualitative and quantitative determination, either in natural resources on Earth and in space or in artificially synthesized materials, electronic and optical devices, optical limiters, sensors, polymers, solar cells, nanophotonic lenses, diagnostic and therapeutic agents, pharmaceutical substances, for targeted drug delivery, incorporation of metal atoms, in biomedical engineering, industry, applied optical science, batteries, catalysts and so forth.

1. Introduction

Fullerenes C₆₀ and C₇₀ were first detected in space [1–14] and quantified [5, 6] by means of IR spectroscopy [1–27]. They were found in a series of space environments and astrophysical objects [1–27], such as certain planetary [4–7] and protoplanetary nebulae [7], carbon-rich stars including also R-Coronae Borealis stars [8, 9], postasymptotic giant branch stars, and young stellar objects [10], in the interstellar medium, in reflection nebulae [1–3, 11–14], as well as in some resources on Earth [3, 15].

For the identification of the basic fullerenes, the knowledge of the infrared band position and band widths as well as the evolution of these parameters with temperature was necessary [1–25]. Quantitative assessment of fullerenes C₆₀ and C₇₀ required knowledge about intensities of their IR absorption bands [3, 5, 6, 26–28].

Their relative abundance in space, for example, an abundance of about 0.35% in certain planetary nebulae, was estimated through the molar absorptivity and integrated molar absorptivity of the infrared maxima measured in laboratory [5, 6].

Another useful method for the identification and quantitative determination of fullerenes can be electronic absorption spectroscopy due to their transitions in the spectral range comprised between 190 and 1500 nm, where it is known that the space is rich in a number of yet unassigned electronic transitions belonging to molecules and radicals [28, 29].

It should be expected also that the higher fullerenes can be found and quantified in space because of their exceptional stability toward high temperatures and cosmic rays [1–3, 30–34], as well as the possibilities of their formation through coalescence of smaller fullerenes by laser ablation of carbon and dehydrogenation of hydrogenated fullerenes, fulleranes [1–3, 30–37].

The IR and electronic absorption spectra as well as their dependence on temperature that are necessary for the qualitative detection of the higher fullerenes, such as C₇₆-D₂, the only stable C₇₆ isomer of D₂ symmetry [1–3, 38–61], isolated by the new advanced chromatographic methods [2, 3, 38–45], were studied in the previous works [2, 3, 38–61].

It is important to mention that all of the experimentally observed infrared and electronic absorption bands of the isolated C₇₆-D₂ in this research [2, 3, 38–44] are in excellent agreement with the theoretical calculations for this molecule [46–49].

The aim of this study was to determine the novel IR and UV/VIS spectroscopic parameters that are necessary for the quantitative assessment of C₇₆-D₂.

In the previous work [3], the molar extinction coefficients and the integrated molar extinction coefficients of the main convoluted or integral IR absorption bands with some shoulders of this fullerene were determined and reported together with the relative intensities.

Excellent agreement was found between the relative intensities of the main characteristic absorption maxima calculated from and from the values in adequate integration ranges [3].

In this article, the molar absorptivity and the integrated molar absorptivity of the entire series of all the observed various characteristic and new deconvoluted or separated absorption maxima and shoulders were determined. In addition, the integrated molar absorptivity of several convoluted absorption bands with some shoulders of C₇₆-D₂ in different and new relevant integration ranges were determined. The molar extinction coefficients of its UV/VIS absorption bands were also determined.

The molar absorptivity and the integrated molar absorptivity in the applied integration ranges of the corresponding main and characteristic absorption bands, both separated and integral, in all the IR and UV/VIS spectra of the chromatographically purified C₇₆-D₂ samples from this research [2, 3, 38–44] are in excellent agreement.

The obtained new research results in the recent [3] and current IR and UV/VIS spectroscopic study of the higher fullerene C₇₆-D₂ are important for its quantitative determination.

All the presented IR and UV/VIS data will significantly contribute to better understanding of the spectroscopic properties of C₇₆-D₂, which is important both for its identification and quantitative assessment, either in natural resources or in artificially synthesized materials.

2. Experimental Methods

In the first phase of this research, C₆₀, C₇₀ [21–23], and the higher fullerenes, mainly C₇₆ and C₈₄ [2, 3, 38–45], were Soxhlet extracted with a series of different and previously unapplied solvents or combinations of solvents from the samples of the carbon soot produced by an electric arc (MER Corporation, Tucson, USA). The extraction procedures were performed until the complete disappearance of color in a Soxhlet extraction thimble. Solvents used were n-heptane, toluene, chlorobenzene, p-xylene, a mixture of o/m/p-xylene, and pyridine, as well as the successive use of toluene and chlorobenzene and p-xylene and pyridine. The yields as well as the compositions of all the extracts were determined by spectroscopic and chromatographic methods. The procedures for increases of fullerene yields and for additional selective extraction of higher order fullerenes were found [2, 3, 21–23, 38–45].

In the second phase, C₆₀, C₇₀, and the higher fullerenes C₇₆ and C₈₄ (the only stable C₆₀-Ih, C₇₀-D5h, and C₇₆-D₂ isomers of the first three mentioned fullerenes and the most abundant, stable C₈₄ isomer of D₂ symmetry) were chromatographically separated from the obtained extracts of the carbon soot on the activated Al₂O₃ columns by new and advanced methods [2, 3, 38–45].

The main difference and advantage of these methods [2, 3, 38–45], in comparison to previous methods under pressure [53–61], is the isolation of the purified stable isomers of the higher fullerenes C₇₆ and C₈₄ (the C₇₆-D₂ and C₈₄-D₂:22 isomers) successively after the basic fullerenes in one phase of each of the processes under atmospheric pressure and smaller flow of 1.5 mL/min in increased milligram yields. The elution was performed continuously with several different original, defined gradients of solvents: from pure hexane or 5% toluene in hexane to pure toluene. The amounts of the initial materials used were as follows: fullerene extracts, 10 mg, and finely granulated Al₂O₃, 50 g, activated for 2 h at 105°C, and eluent (1.5 to 1.75 L) per chromatographic separation [2, 3, 38–45]. Starting from 10 mg of the soluble soot extract, in average ca. 1 mg of C₇₆ and ca. 1 mg of C₈₄ were isolated in purified form per one chromatographic process or up to few milligrams in some cases. The time spent on the purification processes was from 16.7 to 19.4 h [3, 42, 43].

The other advantages of the developed methods [2, 3, 38–45], in comparison to previous methods [53–61], are the use of significantly smaller amounts of the initial materials as well as less expensive laboratory equipment. In these methods [2, 3, 38–45], the entire materials and energy expense, the time spent on the purification processes, and environmental pollution were decreased using smaller amounts of less toxic solvents. The yields and the purities of the isolated fullerenes were increased or maximized [2, 3, 42, 43].

Purification of the higher fullerenes under pressure on a preparative scale, either by flash chromatography or by HPLC, generally required larger amounts of the initial materials repeated chromatography, and the fullerenes were obtained in smaller yields [53–61] compared to our results [2, 3, 38–45]. This was discussed and presented in more detail in the previous articles [3, 42, 43].

2.1. Measurement of the IR Spectra, the Molar Absorptivity, and Integrated Molar Absorptivity of Deconvoluted and Convoluted Absorption Bands of C₇₆-D₂

The IR spectra of the C₇₆-D₂ samples, isolated by the new and advanced chromatographic methods and processes [2, 3, 38–44], were recorded on a Thermo Scientific FT-IR spectrometer Nicolet IR-6700 by the KBr disk technique in the range of 400–2000 cm⁻¹ at a resolution of 1 cm⁻¹ in the transparence mode formerly for its qualitative detection [2]. In the previous [3] and this article, the IR spectra of the isolated C₇₆-D₂ samples were recorded in the absorption mode for determination of novel parameters for its quantitative determination.

Chromatographically isolated C₇₆-D₂ sample (0.196 mg) was mixed with 100.4 mg of KBr. The obtained powder was compressed at 4 tons/cm² with the Perkin Elmer press. The resulting pellet was placed in the FT-IR spectrometer. Measurement of the intensities (heights) of the entire new series of C₇₆-D₂ absorption bands as well as of the integrated intensities of both all deconvoluted absorption maxima and shoulders and of convoluted absorption bands with some shoulders of this fullerene in different integration ranges with automatic subtraction of the baseline was made possible through the OMNIC software from Thermo Scientific, dedicated to the FT-IR spectrometer. The method and software used in this study have also been recently used for the measurement of relative intensities of IR absorption bands of the basic fullerenes C₆₀, C₇₀, and their hydrogenated derivative fulleranes [25–27], as well as of the main convoluted absorption bands of the higher fullerenes C₇₆-D₂ and C₈₄-D₂:22 [3].

The mass of the resulting pellet was 100.6 mg, and the percentage of carbon determined by the elemental analysis was 0.195. Its measured thickness () was 1.205 mm~0.1205 cm, diameter () was 0.7 cm, and the half diameter () was 0.35 cm.

The volume of the pellet () was determined from the abovementioned and parameters by the equation . The obtained values of the volume and the thickness of the pellet were also confirmed using KBr density (2.753 g/cm³) [3, 26] and the mass of the pellet.

Concentration () of fullerene C₇₆ in this pellet was calculated using the above given mass of C₇₆ in the pellet, its molar mass of 912.76 g/mol, and the volume of the pellet. The value determined for the applied C₇₆-D₂ sample in KBr pellet from the abovementioned experimental parameters was 1409.9 L cm⁻¹ mol⁻¹, ca. 1410 L cm⁻¹ mol⁻¹.

2.2. Measurement of the UV/VIS Spectra and the Molar Absorptivity of Absorption Bands of C₇₆-D₂

The UV/VIS spectra of the chromatographically isolated C₇₆-D₂ samples by the new improved methods were recorded on the GBC Cintra 40 spectrophotometer in the region from 200 to 900 nm for its qualitative detection previously [2, 38–43], as well as for the quantitative determination in this article. Solutions of fullerene C₇₆ in hexane, conc. 10⁻⁵ mol/dm³ were used. The thickness of the cuvette was 1 cm.

The value determined for the C₇₆-D₂ sample in n-hexane from the abovementioned experimental parameters was 100,000 L cm⁻¹ mol⁻¹.

3. Results and Discussion

In this article, the molar absorptivity and the integrated molar absorptivity of the observed series of various characteristic and new for both deconvoluted and convoluted IR absorption bands in different integration ranges of the C₇₆-D₂ isomer were determined. The molar absorptivity of its UV/VIS absorption bands was also determined.

The original characteristic and new IR spectrum of the chromatographically isolated C₇₆-D₂ sample are obtained in the absorption mode in this article, Figure 1, in order to find the abovementioned novel parameters for its quantitative determination. This spectrum was previously provided in transparence mode [2] for its qualitative determination.

Figure 1: The IR(KBr) absorption spectrum of the isolated C₇₆-D₂ sample.

The main three most intense dominant C₇₆ maxima registered in this research [2, 3, 38–44] appear at 967 cm⁻¹; 1082 cm⁻¹ with the shoulders at 1122, 1101, 1056, and 1024 cm⁻¹; and at 1187 cm⁻¹ with the shoulders at 1209 and 1162 cm⁻¹ in the central part of the region relevant for the identification of fullerenes from ca. 400 to 1800 cm⁻¹. Characteristic absorption bands unique to C₇₆ are present in the first relevant part of the spectrum at 892 and 823 cm⁻¹ with a neighboring band at 789 cm⁻¹, at 705 cm⁻¹ with the shoulders at 743 and 729 cm⁻¹, at 646 cm⁻¹ with a shoulder at 661 cm⁻¹, followed by a maximum at 603 cm⁻¹. Several other C₇₆ absorption bands appear at 533 cm⁻¹ with a shoulder at 555 cm⁻¹, at 487 cm⁻¹ with a shoulder at 507 cm⁻¹, at 436 cm⁻¹ with a shoulder at 461 cm⁻¹, and at 405 cm⁻¹. Pronounced and intense maxima are present in the higher frequency region at 1386 cm⁻¹ with the shoulders at 1399 and 1364 cm⁻¹, at 1461 cm⁻¹ with a neighboring band at 1493 cm⁻¹, and at 1633 and 1734 cm⁻¹ with the shoulders at 1681 cm⁻¹ and 1713 cm⁻¹, respectively. Maximum at 1312 cm⁻¹ appears, followed by the bands at 1276 cm⁻¹, with a shoulder at 1291 cm⁻¹ and at 1247 cm⁻¹. Weak absorption features are also observed at 1552, 1533, and 1339 cm⁻¹. Complete absorption [2] in this spectrum corresponds to the theoretical predictions for C₇₆-D₂, as well as for its dianion [46, 47].

The IR spectra of all the chromatographically isolated C₇₆-D₂ samples from this research have similar properties. All the observed vibrational frequencies and the general pattern of these spectra [2, 3, 38–44] are in agreement with the semiempirical QCFF/PI and DFT theoretical calculations for C₇₆-D₂, as well as for its dianion C₇₆-D₂²⁻ [2, 3, 42–44, 46, 47].

From the presented IR absorption spectrum Figure 1, the values of absorbance have been determined for all the separated absorption maxima and shoulders using the OMNIC software subtracting automatically the base line. Determination of molar absorptivity of the entire series of deconvoluted IR absorption bands of the C₇₆-D₂ isomer at a given wave number was achieved through (1), previously applied for its main convoluted infrared absorption bands for C₆₀ and C₇₀, as well as hydrogenated fullerenes [3, 25–27, 62], according to Lambert and Beer law using the absorbance read at a given wave number.

It was found that the peak height measurements that correspond to the absorbance are sensitive to changes in the resolution of the spectrometers used [25–27, 62] and to changes in temperature and smaller chemical shifts of characteristic absorption bands (within 1–3 cm⁻¹) in some cases. Theoretical calculations [46, 47] also predict the possibility of appearance of very close or different out of the numerous possible IR vibration modes C₇₆-D₂. The measurement of the integrated intensity that represents the area below a corresponding absorption band measured in adequate integration range is much less sensitive to instrumental resolution [25–27, 62] and temperature as well as smaller shifts of absorption bands than the peak height measurement.

Thus in this article also, the integrated intensity of both deconvoluted and convoluted absorption bands in different integration ranges was determined from the presented infrared spectrum in a mode of the isolated C₇₆-D₂ sample, Figure 1, using the OMNIC software and subtracting automatically the baseline. The integrated molar absorptivity expressed in cm mol⁻¹ or 10⁻⁵ Km mol⁻¹ was calculated by (2), previously applied for its main convoluted absorption bands for the basic fullerenes as well as for fulleranes [3, 25–27, 62].

In this equation, is the wavelength, and is the molar absorptivity integrated over the whole band. In practice, by substituting (1) into (2), we get [3, 25–27, 62]

The molar absorptivity and the integrated molar absorptivity in adequate integration range calculated according to (1) and (2) of all the observed [2, 3] deconvoluted absorption bands of the higher fullerene C₇₆-D₂ in this spectrum are reported in Table 1.

Table 1: The molar absorptivity and the integrated molar absorptivity in adequate integration range of deconvoluted absorption bands of C₇₆-D₂.

a,b
(cm⁻¹)

(L cm⁻¹ mol⁻¹)
Int. range
(cm⁻¹)

(Km mol⁻¹)

1733.8
129.711
1758–1721
1.097

1712.6
81.774
1721–1699
0.017

1680.7
91.643
1684–1678
0.004

1633.1
188.927
1678–1573
6.549

1551.6
16.919
1562–1543
0.022

1533.4
14.099
1542–1513
0.025

1493.4
252.372
1512–1481
2.242

1461.1
320.047
1478–1432
3.953

1398.7
270.701
1416–1396
0.265

1385.6
303.128
1393–1371
0.850

1364.2
146.630
1368–1349
0.230

1338.7
29.608
1349–1326
0.024

1312.4
112.792
1326–1300
0.884

1290.5
81.774
1296–1283
0.010

1275.6
91.643
1282–1263
0.096

1247.6
111.382
1260–1231
0.568

1208.6
174.828
1222–1202
0.234

1187.0
384.903
1200–1168
3.423

1161.6
159.319
1167–1141
0.254

1122.0
131.121
1139–1112
0.219

1101.0
140.990
1110–1099
0.028

1081.6
370.804
1098–1063
3.810

1056.4
112.792
1062–1048
0.027

1024.2
115.612
1039–1005
0.179

967.0
634.455
996–926
13.765

892.2
88.824
908–871
1.107

823.4
64.855
848–809
1.376

788.8
43.707
803–774
0.219

742.9
54.986
750–736
0.010

729.3
67.675
736–717
0.014

704.8
84.594
715–679
0.460

661.1
66.265
678–655
0.240

645.8
76.135
655–632
0.031

602.9
132.531
627–575
1.246

555.5
112.792
570–548
0.038

532.7
126.891
545–520
0.300

507.1
104.333
518–499
0.062

486.6
107.152
499–471
0.344

460.6
71.905
469–453
0.037

436.0
102.923
450–422
0.637

405.2
179.057
421–400
1.799

a[2]. b[3].

The integrated molar absorptivity of convoluted absorption maxima with some absorption shoulders of C₇₆-D₂ in determined, different, and new relevant integration ranges for its quantitative determination as well as identification is presented in Table 2.

Table 2: The integrated molar absorptivity in determined integration ranges of convoluted absorption maxima with some absorption shoulders of C₇₆-D₂.

(cm⁻¹)
Int. range
(cm⁻¹)

(Km mol⁻¹)

1733.8–1712.6
1757–1699
2.163

1633.1–1680.7
1683–1573
6.861

1461.1–1493.4
1512–1432
9.907

1385.6–1398.7
1423–1371
4.457

1385.6–2 ab. shouldersa
1421–1349
13.163

1275.6–1290.5
1298–1264
0.341

1187.0–2 ab. shouldersb
1222–1143
8.481

1081.6–4 ab. shouldersc
1139–1004
7.979

704.8–742.9
774–681
2.168

645.8–661.1
678–632
0.587

532.7–555.5
571–518
0.735

486.6–507.1
518–470
0.746

436.0–460.6
468–422
0.946

aAbsorption maximum at 1386 cm⁻¹ with two absorption shoulders at 1399 and 1364 cm⁻¹. bAbsorption maximum at 1187 cm⁻¹ with two absorption shoulders at 1209 and 1162 cm⁻¹. cAbsorption maximum at 1081.6 cm⁻¹ with four absorption shoulders at 1122, 1101, 1056, and 1024 cm⁻¹.

The molar absorptivity and the integrated molar absorptivity in the mentioned adequate integration ranges of the corresponding main and characteristic absorption bands, both deconvoluted and convoluted, in all the obtained IR spectra of the chromatographically purified C₇₆-D₂ samples from this research [2, 3, 38–44] are in excellent agreement.

In this article also, the original UV/VIS spectrum of the chromatographically isolated C₇₆-D₂ sample previously applied for its identification [39, 40] is presented in Figure 2 for determination of the abovementioned parameters for its quantitative assessment.

Figure 2: The UV/VIS spectrum of the isolated C₇₆-D₂ sample [39, 40].

Relevant C₇₆ absorption maxima [2, 38–43] of decreased relative intensity in comparison to the spectra of the previous fractions C₆₀ and C₇₀ [21–23] appear at 258 and 328 nm [39, 40]. An inflection point occurs at 210 nm, whereas the most intense dominant UV absorption is moved to the region below 200 nm, which is characteristic for C₇₆. Pronounced C₇₆ absorption shoulder is present at 275 nm followed by less intense shoulders at 358 and 378 nm. In the visible part, weak absorption band appears at 405 nm; the absorption is prolonged to 900 nm. Complete absorption in this spectrum [39, 40] corresponds to the theoretical predictions for C₇₆-D₂ [48, 49].

The UV/VIS spectra of all the chromatographically isolated C₇₆-D₂ samples from this research have similar properties. All the observed absorption bands and the general pattern of these spectra [2, 3, 38–44] are in agreement with the semiempirical QCFF/PI and DFT theoretical calculations for C₇₆-D₂ [2, 42, 43, 48, 49].

From the UV/VIS spectrum [39, 40] presented in Figure 2, the values of absorbance of the absorption bands of C₇₆ have been determined. The values of molar absorptivity were calculated according to (1) previously applied for the basic fullerenes and their radical cations as well as fulleranes [28, 29, 62] and reported in Table 3.

Table 3: The molar absorptivity of absorption bands of C₇₆-D₂.

a,b
(nm)

(L cm⁻¹ mol⁻¹)

210.0
140,000

257.7
41,500

275.0
26,500

327.8
11,000

358.0
6000

378.0
4500

405.0
3100

a[39]. b[40].

The molar absorptivity of the observed main and characteristic absorption bands in all the obtained UV/VIS spectra of the chromatographically purified C₇₆-D₂ samples from this research [2, 38–43] is in excellent agreement.

The aforementioned change of the spectral parameters of the C₇₆-D₂ isomer compared to C₆₀ and C₇₀ can also lead to changes of refraction features that can be useful for its application in the fullerene-based optoelectronic materials and devices, such as nanophotonic lenses with advanced properties. The results of the recent investigations [63–67] show also that fullerene nanomaterials incorporated in standard, basic (commercial) materials, such as poly(methyl methacrylate) for the rigid gas permeable and poly(2-hydroxyethyl methacrylate) for the soft contact lenses, improve their wettability.

4. Conclusion

In this study, the only stable isomer of the higher fullerene C₇₆ of D₂ symmetry was isolated from the carbon soot by new and advanced extraction and chromatographic methods and processes [2, 3, 38–44]. The original and new IR and UV/VIS spectra [39, 40] of the isolated C₇₆-D₂ sample were obtained in the absorption mode over the relevant regions from 400 to 2000 cm⁻¹, as well as from 200 to 900 nm, and presented for determination of novel parameters for its quantitative assessment.

All of the experimentally observed infrared and electronic absorption bands of the isolated C₇₆-D₂ samples from this research [2, 3, 38–44] are in excellent agreement with the theoretical calculations for this molecule [46–49], which is important for the qualitative detection [2, 3].

In the previous article [3], the molar extinction coefficients and the integrated molar extinction coefficients of the main convoluted IR absorption bands of the higher fullerene C₇₆-D₂ were determined and reported together with the relative intensities.

Excellent agreement was obtained between the relative intensities of the main absorption maxima calculated from and from the values in adequate integration ranges [3].

In this article, the molar absorptivity and the integrated molar absorptivity of the entire series of the observed various characteristic and new deconvoluted IR absorption maxima and shoulders of the isolated C₇₆-D₂ isomer were determined at room temperature in the KBr matrix. In addition, the integrated molar absorptivity of several convoluted absorption bands with some shoulders in different and relevant integration ranges was determined. The molar absorptivity of its UV/VIS absorption bands was also determined.

It should be mentioned that the molar extinction coefficients and the integrated molar extinction coefficients in the mentioned adequate integration ranges of the corresponding main and characteristic absorption bands, both separated and convoluted, in all the IR and UV/VIS spectra of the chromatographically purified C₇₆-D₂ samples from this research [2, 3, 38–44] are in excellent agreement.

The obtained new IR and UV/VIS spectroscopic results and parameters of the higher fullerene C₇₆-D₂ are important for its quantitative determination.

All the presented data will significantly contribute to better understanding of the IR and UV/VIS spectroscopic properties of the C₇₆-D₂ isomer. This is important both for its identification and quantitative assessment, either in natural resources or in artificially synthesized materials, electronic and optical devices, optical limiters, sensors, polymers, solar cells, nanophotonic lenses, diagnostic and therapeutic agents such as for diabetes, incorporation of metal atoms, targeted drug delivery in biomedical engineering, industry, applied optical science, batteries, catalysts, synthesis of diamond, and so forth.

Additional Points

Figure 2 is an intellectual property of Tamara Jovanovic and Djuro Koruga. The new technological process for extraction, chromatography, and characterization of the basic and the higher fullerenes from carbon soot, the intellectual property office of Serbia, Belgrade, no. 985/09 A-59/09, 2009.

Conflicts of Interest

The authors declare that there are no conflicts of interest regarding the publication of this paper.

Acknowledgments

The authors are grateful to Professor Dr. Branimir Jovancicevic, Department of Applied Chemistry, Faculty of Chemistry, University of Belgrade, for valuable help and support during the experimental part of the work and to the Ministry of Education, Science and Technological Development of the Republic of Serbia and the University of Belgrade for financial support of this research (Project III 45009).

References

F. Cataldo, Y. Hafez, and S. Iglesias-Groth, “FT-IR spectra of fullerenes C₇₆, C₇₈ and C₈₄ at temperatures between −180°C and +250°C,” Fullerenes, Nanotubes, and Carbon Nanostructures, vol. 22, no. 10, pp. 901–913, 2014.

T. Jovanović, Đ. Koruga, and B. Jovančićević, “Recent advances in IR and UV/VIS spectroscopic characterization of the C₇₆ and C₈₄ isomers of D₂ symmetry,” Journal of Nanomaterials, vol. 2014, Article ID 701312, 11 pages, 2014.

T. Jovanović, Đ. Koruga, and B. Jovančićević, “The IR spectra, molar absorptivity, and integrated molar absorptivity of the C₇₆-D₂ and C₈₄-D₂:22 isomers,” Journal of Nanomaterials, vol. 2017, Article ID 4360746, 10 pages, 2017.

J. Cami, J. Bernard-Salas, E. Peeters, and S. E. Malek, “Detection of C₆₀ and C₇₀ in a young planetary nebula,” Science, vol. 329, no. 5996, pp. 1180–1182, 2010.

D. A. García-Hernández, S. Iglesias-Groth, J. A. Acosta-Pulido et al., “The formation of fullerenes: clues from new C₆₀, C₇₀, and (possible) planar C₂₄ detections in Magellanic cloud planetary nebulae,” The Astrophysical Journal Letters, vol. 737, no. 2, p. L30, 2011.

D. A. García-Hernández, E. Villaver, P. García-Lario et al., “Infrared study of fullerene planetary nebulae,” The Astrophysical Journal, vol. 760, no. 2, p. 107, 2012.

Y. Zhang and S. Kwok, “Detection of C₆₀ in the protoplanetary nebula IRAS 01005+7910,” The Astrophysical Journal, vol. 730, no. 2, p. 126, 2011.

D. A. García-Hernández, N. K. Rao, and D. L. Lambert, “Are C₆₀ molecules detectable in circumstellar shells of r coronae borealis stars?” The Astrophysical Journal, vol. 729, no. 2, p. 126, 2011.

G. C. Clayton, D. M. Kelly, J. H. Lacy, I. R. Little-Marenin, P. A. Feldman, and P. F. Bernath, “A mid-infrared search for C₆₀ in R Coronae Borealis stars and IRC+10216,” Astronomical Journal, vol. 109, no. 5, pp. 2096–2103, 1995.

K. R. G. Roberts, K. T. Smith, and P. J. Sarre, “Detection of C60 in embedded young stellar objects, a Herbig Ae/Be star and an unusual post‐asymptotic giant branch star,” Monthly Notices of the Royal Astronomical Society, vol. 421, no. 4, pp. 3277–3285, 2012.

K. Sellgren, M. W. Werner, J. G. Ingalls, J. D. T. Smith, T. M. Carleton, and C. Joblin, “Confirmation of C₆₀ in the reflection nebula NGC 7023,” EAS Publications Series, vol. 46, pp. 209–214, 2011.

G. H. Herbig, “The search for interstellar C₆₀,” The Astrophysical Journal, vol. 542, no. 1, pp. 334–343, 2000.

S. Iglesias-Groth, “Fullerenes and the 4430 Å diffuse interstellar band,” The Astrophysical Journal, vol. 661, no. 2, pp. L167–L170, 2007.

B. H. Foing and P. Ehrenfreund, “Detection of two interstellar absorption bands coincident with spectral features of C₆₀⁺,” Nature, vol. 369, no. 6478, pp. 296–298, 1994.

S. Hameroff, J. Withers, R. Loufty, M. Sundareshan, and D. Koruga, Fullerene C60: History, Physics, Nanobiology, Nanotechnology, Elsevier Science Publishers, Amsterdam, The Netherlands, 1993.

W. Krätschmer, L. D. Lamb, K. Fostiropoulos, and D. R. Huffman, “Solid C₆₀: a new form of carbon,” Nature, vol. 347, no. 6291, pp. 354–358, 1990.

W. Krätschmer, K. Fostiropoulos, and D. R. Huffman, “The infrared and ultraviolet absorption spectra of laboratory produced carbon dust: evidence for the presence of the C₆₀ molecule,” Chemical Physics Letters, vol. 170, no. 2-3, pp. 167–170, 1990.

D. M. Cox, S. Behal, M. Disko et al., “Characterization of C₆₀ and C₇₀ clusters,” Journal of the American Chemical Society, vol. 113, no. 8, pp. 2940–2944, 1991.

D. S. Bethune, G. Meijer, W. C. Tang et al., “Vibrational Raman and infrared spectra of chromatographically separated C₆₀ and C₇₀ fullerene clusters,” Chemical Physics Letters, vol. 179, no. 1-2, pp. 181–186, 1991.

J. P. Hare, T. J. Dennis, H. W. Kroto et al., “The IR spectra of fullerene-60 and -70,” Journal of the Chemical Society, Chemical Communications, no. 6, p. 412, 1991.

T. Jovanovic, D. Koruga, B. Jovancicevic, and J. Simic-Krstic, “Modifications of fullerenes extractions and chromatographies with different solvents,” Fullerenes, Nanotubes, and Carbon Nanostructures, vol. 11, no. 4, pp. 383–394, 2003.

T. Jovanović, D. Koruga, P. Polić, and G. Dević, “Extraction, separation and characterization of fullerenes from carbon soot,” Materials Science Forum, vol. 413, pp. 59–64, 2003.

T. Jovanovic, D. Koruga, B. Jovancicevic, and J. Simic-Krstic, “Improvement in separation of nanostructured carbon clusters C₆₀ and C₇₀,” International Journal of Nanoscience, vol. 2, no. 3, pp. 129–140, 2003.

F. Cataldo, S. Iglesias-Groth, and A. Manchado, “Low and high temperature infrared spectroscopy of C₆₀ and C₇₀ fullerenes,” Fullerenes, Nanotubes, and Carbon Nanostructures, vol. 18, no. 3, pp. 224–235, 2010.

S. Iglesias-Groth, F. Cataldo, and A. Manchado, “Infrared spectroscopy and integrated molar absorptivity of C₆₀ and C₇₀ fullerenes at extreme temperatures,” Monthly Notices of the Royal Astronomical Society, vol. 413, no. 1, pp. 213–222, 2011.

F. Cataldo, S. Iglesias-Groth, and A. Manchado, “On the molar extinction coefficient and integrated molar absorptivity of the infrared absorption spectra of C₆₀ and C₇₀ fullerenes,” Fullerenes, Nanotubes, and Carbon Nanostructures, vol. 20, no. 3, pp. 191–199, 2012.

F. Cataldo, S. Iglesias-Groth, D. A. Garcia-Hernandez, and A. Manchado, “Determination of the integrated molar absorptivity and molar extinction coefficient of hydrogenated fullerenes,” Fullerenes, Nanotubes, and Carbon Nanostructures, vol. 21, no. 5, pp. 417–428, 2013.

F. Cataldo, D. A. García-Hernández, A. Manchado, and S. Iglesias-Groth, “Spectroscopy of fullerenes, fulleranes and PAHs in the UV, visible and near infrared spectral range,” Proceedings of the International Astronomical Union, vol. 9, no. S297, pp. 294–296, 2013.

F. Cataldo, S. Iglesias-Groth, and Y. Hafez, “On the molar extinction coefficients of the electronic absorption spectra of C60 and C70 fullerenes radical cation,” European Chemical Bulletin, vol. 2, no. 12, 2013.

J. Cioslowski, “Heats of formation of higher fullerenes from ab initio Hartree-Fock and correlation energy functional calculations,” Chemical Physics Letters, vol. 216, no. 3–6, pp. 389–393, 1993.

F. Cataldo, G. Strazzulla, and S. Iglesias-Groth, “Stability of C60 and C70 fullerenes toward corpuscular and γ radiation,” Monthly Notices of the Royal Astronomical Society, vol. 394, no. 2, pp. 615–623, 2009.

S. Iglesias-Groth, “Hydrogenated fulleranes and the anomalous microwave emission of the dark cloud LDN 1622,” Monthly Notices of the Royal Astronomical Society, vol. 368, no. 4, pp. 1925–1930, 2006.

F. Cataldo and S. Iglesias-Groth, “On the action of UV photons on hydrogenated fulleranes C60H36 and C60D36,” Monthly Notices of the Royal Astronomical Society, vol. 400, no. 1, pp. 291–298, 2009.

F. Cataldo and S. Iglesias-Groth, Eds., Fulleranes: The Hydrogenated Fullerenes, Springer, Berlin, Germany, 2009.

C. Yeretzian, K. Hansen, F. Diederichi, and R. L. Whetten, “Coalescence reactions of fullerenes,” Nature, vol. 359, no. 6390, pp. 44–47, 1992.

B. Kubler, E. Millon, J. J. Gaumet, and J. F. Muller, “Formation of high mass Cn clusters (n > 100) by laser ablation/desorption coupled with mass spectrometry,” Fullerene Science and Technology, vol. 4, no. 6, pp. 1247–1261, 1996.

F. Cataldo and Y. Keheyan, “On the mechanism of carbon clusters formation under laser irradiation. The case of diamond grains and solid C₆₀ fullerene,” Fullerenes, Nanotubes, and Carbon Nanostructures, vol. 10, no. 4, pp. 313–332, 2002.

T. Jovanovic, D. Koruga, B. Jovancicevic, and J. Simic-Krstic, “Advancement of the process for extraction, chromatography and characterization of fullerenes,” Fullerenes, Nanotubes, and Carbon Nanostructures, vol. 17, no. 2, pp. 135–150, 2009.

T. Jovanovic and D. Koruga, “The new technological process for extraction, chromatography and characterization of the basic and the higher fullerenes from carbon soot,” The intellectual property office of Serbia, Belgrade, The intellectual property office of the Republic of Serbia, Belgrade. Faculty of Mechanical Engineering, University of Belgrade, 2009, Number 985/09 A-59/09.

T. Jovanovic, D. Koruga, B. Jovancicevic, V. Vajs, and G. Devic, “Comparative spectroscopic characterization of the basic and the higher fullerenes,” Fullerenes, Nanotubes, and Carbon Nanostructures, vol. 21, no. 1, pp. 64–74, 2013.

T. Jovanovic, D. Koruga, and B. Jovancicevic, “Isolation and characterization of the higher fullerenes from carbon soot,” Fullerenes, Nanotubes, and Carbon Nanostructures, vol. 19, no. 4, pp. 309–316, 2011.

T. Jovanovic, D. Koruga, and B. Jovancicevic, “Advances in chromatographic separation on Al₂O₃ and spectroscopic characterization of the higher fullerenes,” Fullerenes, Nanotubes, and Carbon Nanostructures, vol. 22, no. 4, pp. 384–396, 2014.

T. Jovanovic and D. Koruga, “Recent advances in chromatographic separation and spectroscopic characterization of the higher fullerenes C₇₆ and C₈₄,” Recent Patents on Nanotechnology, vol. 8, no. 1, pp. 62–75, 2014.

T. Jovanovic and D. Koruga, “The electronic structure and vibrational frequencies of the stable C₇₆ isomer of D₂ symmetry: theory and experiment,” Chemical Physics Letters, vol. 577, pp. 68–70, 2013.

T. Jovanovic, D. Koruga, and B. Jovancicevic, “The electronic structure and vibrational frequencies of the stable C₈₄ isomer of D₂ symmetry: theory and experiment,” Diamond and Related Materials, vol. 44, pp. 44–48, 2014.

G. Orlandi, F. Zerbetto, P. W. Fowler, and D. E. Manolopoulos, “The electronic structure and vibrational frequencies of the stable C₇₆ isomer of D₂ symmetry,” Chemical Physics Letters, vol. 208, no. 5-6, pp. 441–445, 1993.

O. Hampe, M. Neumaier, A. D. Boese, J. Lemaire, G. Niedner-Schatteburg, and M. M. Kappes, “Infrared multiphoton electron detachment spectroscopy of C₇₆²⁻,” The Journal of Chemical Physics, vol. 131, no. 12, p. 124306, 2009.

K. Harigaya and S. Abe, “Optical absorption spectra and geometric effects in higher fullerenes,” Journal of Physics: Condensed Matter, vol. 8, no. 42, pp. 8057–8066, 1996.

S. Saito, S. I. Sawada, and N. Hamada, “Electronic and geometric structures of C₇₆ and C₈₄,” Physical Review B, vol. 45, no. 23, pp. 13845–13848, 1992.

D. E. Manolopoulos, “Faraday communications. Proposal of a chiral structure for the fullerene C₇₆,” Journal of the Chemical Society, Faraday Transactions, vol. 87, no. 17, pp. 2861-2862, 1991.

D. E. Manolopoulos and P. W. Fowler, “Molecular graphs, point groups, and fullerenes,” The Journal of Chemical Physics, vol. 96, no. 10, pp. 7603–7614, 1992.

O. T. Ehrler, F. Furche, J. Mathias Weber, and M. M. Kappes, “Photoelectron spectroscopy of fullerene dianions C76(2-), C78(2-), C84(2-),” The Journal of Chemical Physics, vol. 122, no. 9, article 094321, 2005.

F. Diederich, R. Ettl, Y. Rubin et al., “The higher fullerenes: isolation and characterization of C₇₆, C₈₄, C₉₀, C₉₄, and C₇₀O, an oxide of D5h-C₇₀,” Science, vol. 252, no. 5005, pp. 548–551, 1991.

K. Jinno, H. Matsui, H. Ohta et al., “Separation and identification of higher fullerenes in soot extract by liquid chromatography-mass spectrometry,” Chromatographia, vol. 41, no. 5-6, pp. 353–360, 1995.

K. Jinno, Y. Sato, H. Nagashima, and K. Itoh, “Separation and identification of higher fullerenes by high-performance liquid chromatography coupled with electrospray ionization mass spectrometry,” Journal of Microcolumn Separations, vol. 10, no. 1, pp. 79–88, 1998.

K. Kikuchi, N. Nakahara, M. Honda et al., “Separation, detection and UV/Visible absorption spectra of fullerenes: C₇₆, C₇₈, and C₈₄,” Chemistry Letters, vol. 20, no. 9, pp. 1607–1610, 1991.

K. Kikuchi, N. Nakahara, T. Wakabayashi et al., “Isolation and identification of fullerene family: C₇₆, C₇₈, C₈₂, C₈₄, C₉₀ and C₉₆,” Chemical Physics Letters, vol. 188, no. 3-4, pp. 177–180, 1992.

R. Ettl, I. Chao, F. Diederich, and R. L. Whetten, “Isolation of C₇₆, a chiral D₂ allotrope of carbon,” Nature, vol. 353, no. 6340, pp. 149–153, 1991.

R. H. Michel, H. Schreiber, R. Gierden et al., “Vibrational spectroscopy of purified C₇₆,” Berichte der Bunsengesellschaft für physikalische Chemie, vol. 98, no. 7, pp. 975–978, 1994.

A. G. Avent, D. Dubois, A. Pénicaud, and R. Taylor, “The minor isomers and IR spectrum of [84]fullerene,” Journal of the Chemical Society, Perkin Transactions 2, no. 10, pp. 1907–1910, 1997.

T. J. S. Dennis, M. Hulman, H. Kuzmany, and H. Shinohara, “Vibrational infrared spectra of the two major isomers of [84] fullerene: C₈₄D₂(IV) and C₈₄D2d(II),” The Journal of Physical Chemistry B, vol. 104, no. 23, pp. 5411–5413, 2000.

N. B. Colthup, L. H. Daly, and S. E. Wiberley, Introduction to Infrared and Raman Spectroscopy, Academic Press, San Diego, California, USA, 3rd edition, 1990.

T. Jovanović and D. Koruga, “Optical absorption properties and applications of fullerenes,” in Proceedings of the 14th Yougoslav Materials Research Society Conference “YUCOMAT ‘12”, p. 122, Materials Research Society of Serbia, Herceg-Novi, Montenegro, 2012.

D. Stamenković, N. Jagodić, M. Conte, N. Ilanković, T. Jovanović, and D. Koruga, “Optical properties of nanophotonic contact lenses,” in Proceedings of the 12th Yougoslav Materials Research Society Conference "YUCOMAT '10", p. 177, Materials Research Society of Serbia, Herceg-Novi, Montenegro, 2010.

A. Mitrović, D. Popović, V. Miljković, and D. Koruga, “Mechanical properties of nanophotonic soft contact lenses based on poly (2-hydrohzethil methacrylate) and fullerenes,” Structural Integrity and Life, vol. 16, no. 1, pp. 39–42, 2016.

T. Jovanovic, D. Koruga, B. Jovancicevic, and D. Stamenkovic, “IR spectroscopy of the higher fullerene C₇₆-D₂ for its qualitative and quantitative determination,” in Innovation Center of Faculty of Mechanical Engineering, Faculty of Mechanical Engineering, University of Belgrade, Proceedings of the International Conference on Experimental and Numerical Investigations and New Technologies “CNN TECH 2017”, p. 24, Zlatribor, Serbia, 2017.

T. Jovanović, D. Koruga, B. Jovančićević, A. Mitrović, D. Stamenković, and I. Rakonjac, “Comparative spectroscopic characterization of fullerene nanomaterials,” in Proceedings of the 19th Yougoslav Materials Research Society Conference “YUCOMAT ‘17”, Materials Research Society of Serbia, p. 107, Herceg-Novi, Montenegro, 2017.