Five new structural ferrocene derivatives (
Ferrocene derivatives have attracted considerable attention for their potential applications as nonlinear optical devices, functional materials in electrochemical sensor [
L-Cysteine (L-Cys) plays a crucial role in both bio- and environmental chemistry and can be applied in many biochemical processes and diagnosis of disease states. Especially, L-Cys provides a modality for the intramolecular crosslinking of proteins through disulfide bonds to support their secondary structures and functions. Therefore, it is very important to develop simple and effective methods to trace L-Cys detection. Many methods, such as spectrometric method [
The oxidation of L-Cys at Hg, Au, Ag, Pt, and diamond electrodes has been reported [
Synthetic routes of ferrocene derivatives.
2-Chloro-4,6-dimethoxy-[1,3,5]triazine (CDMT),
Ferrocene carboxylic acid
Light yellow solid (0.75 g, 86% yield). M.p. 173°C, IR (cm−1): 3235 (NH), 3039 (=C–H), 2931 (C–H), 1701 (O=C–O–), 1598 (C=C), 1542 (C=N), 1182 (C–O); 1H NMR (CDCl3)
Ferrocene carboxylic acid
Light yellow solid (0.638 g, 92% yield). M.p. 141-142°C, IR (cm−1): 3035 (=C–H), 1776 (O=C–O–), 1441 (C=C), 1261 (C=N), 1054 (C–O), 768 (Ph); 1H NMR (CDCl3)
The detailed process for synthesis of
The detailed process for synthesis of
Ferrocene carboxylic acid
Light yellow solid (0.863 g, 92% yield). M.p. 90–92°C, FTIR (cm−1): 3104 (=C–H), 2951 (C–H), 1747 (O=C–O), 1577 (C=C), 1469 (C=N), 1366 (C–O); 1H NMR (400 MHz, CDCl3)
Compound
The detailed process for preparing the solutions of 1.5 ×10−2 mol L−1
A GCE was polished with 0.1
A modified GCE was prepared by placing 5
The modified GCE, a twisted platinum wire electrode, and Ag/AgCl electrode were dipped into 20 mL (V/V, 1 : 1) water solution of 6.0 × 10−3 mol L−1 L-Cys and 0.1 mol L−1 NaNO3. The Ag/AgCl electrode was connected to the main body of the cell through a luggin capillary whose end was connected on the modified GCE and positioned close to the electrode surface. The solution was thoroughly flushed with high purity nitrogen for 5 min before each run to remove the oxygen from the solution in the electrochemical cell. All experiments were carried out at room temperature.
Ferrocene derivatives (
There showed three kinds of proton signals for ferrocene core of the ferrocene derivatives (
Characteristic fragments of 1H spectra of ferrocene ring in ferrocene derivatives
X-ray diffraction data for
Crystallographic data and structure refinement for
Crystal Data |
|
Experical formula | C17H12ClFeN3O2 |
MW | 381.60 |
Crystal system | monoclinic |
Space group | P2(1)/c |
|
9.6361(8) |
|
13.7876(7) |
|
13.1082(8) |
|
90.00 |
|
108.881(8) |
|
90.00 |
|
1647.83(19) |
|
4 |
|
1.538 |
|
8.958 |
|
776 |
|
4.80 to 74.56 |
Reflections collected/unique | 6006/3248 |
|
0.0230 |
|
|
|
|
GOF on |
0.999 |
Selected bond lengths
(Ǻ) and angles (°) for
Bond lengths |
Bond angle (°) | ||
---|---|---|---|
Fe(1)–C(9) | 2.007(3) | C(9)–Fe(1)–C(8) | 41.50(12) |
Fe(1)–C(1) | 2.025(3) | C(9)–Fe(1)–C(2) | 153.96(14) |
C(9)–C(11) | 1.445(4) | C(9)–Fe(1)–C(5) | 127.51(17) |
C(11)–O(12) | 1.185(4) | C(8)–Fe(1)–C(10) | 69.73(14) |
O(13)–N(14) | 1.362(3) | O(12)–C(11)–C(9) | 130.8(3) |
N(14)–C(22) | 1.361(3) | O(13)–N(14)–N(15) | 118.6(3) |
C(20)–Cl(23) | 1.730(3) | N(16)–C(17)–C(22) | 109.1(3) |
N(15)–N(16) | 1.295(4) | N(14)–C(22)–C(21) | 133.8(2) |
C(19)–C(20) | 1.408(4) | C(19)–C(20)–Cl(23) | 117.6(2) |
Crystal structure of
The preliminarily electrochemical oxidation of L-Cys with the nafion-ferrocene derivatives modified GCE in 0.1 mol L−1 different supporting electrolyte solutions, such as NaCl, NaNO3, NaAc, and Na2SO4, has been investigated by cyclic voltammetry. The results (Figure
Cyclic voltammograms of (a) nafion modified GCE in 0.1 mol L−1 NaNO3; (b) nafion modified GCE in solution of 0.1 mol L−1 NaNO3 and 6.0 × 10−3 mol L−1 L-Cys; (c)
In this study, five ferrocene derivatives (
The authors declare that there is no conflict of interests regarding the publication of this paper.
This work was financially supported by the 973 Key Program of the MOST (2010CB933501, 2012CB821705), the Chinese Academy of Sciences (KJCX2-YW-319, KJCX2-EW-H01), the National Natural Science Foundation of China and the Natural Science Foundation of Fujian Province (2007HZ0001-1, 2009HZ0005-1, 2009HZ0006-1, and 2006L2005), and Postdoctoral Foundation of Fujian Province.