The synthesis and spectral characterization of novel diorganotin complexes with 3-hydroxypyridine-2-carbaldehyde thiosemicarbazone,
Organotin(IV) compounds find wide applications as catalysts and stabilizers, and certain derivatives are used as biocides, as antifouling agents and for wood preservation. It has been observed that several diorganotin adducts show potential as antineoplastic and antituberculosis agents [
Thiosemicarbazone derivatives are of considerable interest due to their antibacterial, antimalarial, antiviral, and antitumor activitiy [
The present paper includes the interaction of SnPh2O (where R is methyl, butyl, and phenyl groups) with 3-Hydroxypyridine-2-carbaldehyde thiosemicarbazone (H2L) and the crystal structure of the complex [SnPh2(L)(DMSO)] (
All reagents were commercially available (Aldrich or Merck) and used as supplied. Solvents were purified and dried according to standard procedures. Melting points (m.p.) were determined in open capillaries and are uncorrected. IR and far-IR spectra were recorded on a Perkin Elmer Spectrum GX Fourier transform spectrophotometer using KBr pellets (4000–400 cm-1) and nujol mulls dispersed between polyethylene disks (400–40 cm-1). The free ligand was dissolved in (CD3)2SO and 1H, 1H–1H COSY and 13C spectra were acquired on a BRUKER 300 MHz spectrometer. Compounds
The ligand was synthesized according to a published procedure [
Dimethyltin(IV) oxide (0.033 g, 0.2 mmole) and 3-hydroxypyridine-2-carbaldehyde Thiosemicarbazone (0.0392 g, 0.2 mmole) in benzene (20 mL) were stirred and were refluxed for 12 hours under azeotropic removal of water (Dean-Stark trap). The resulting clear solution was rotary evaporated under vacuum to a small volume (2 mL), chilled and triturated with diethyl ether to give a white solid. The powder was recrystallized from distilled diethyl ether and dried in vacuo over silica gel to give yellow solid; mp. 228–230°C, Yield 35%. IR (cm-1): 3296 m,
Dibutylltin(IV) oxide (0.0498 g, 0.2 mmole) and 3-hydroxypyridine-2-carbaldehyde Thiosemicarbazone (0.0392 g, 0.2 mmole) in benzene (20 mL) were stirred and were refluxed for 12 hours under azeotropic removal of water (Dean-Stark trap). The resulting clear solution was rotary evaporated under vacuum to a small volume (2 mL), chilled and triturated with diethyl ether to give a white solid. The powder was recrystallized from distilled diethyl ether and dried in vacuo over silica gel to give yellow solid; mp. 126–128°C, Yield 41%. IR (cm-1): 3292 m,
Diphenylltin(IV) oxide (0.0578 g, 0.2 mmole) and 3-hydroxypyridine-2-carbaldehyde thiosemicarbazone (0.0392 g, 0.2 mmole) in benzene (20 mL) were stirred and were refluxed for 12 hours under azeotropic removal of water (Dean-Stark trap). The resulting clear solution was rotary evaporated under vacuum to a small volume (2 mL), chilled and triturated with diethyl ether to give a white solid. The powder was recrystallized from distilled diethyl ether and dried in vacuo over silica gel to give yellow solid : mp. 186–188°C, Yield 34%. IR (cm-1): 3269 m,
Crystals of complex
X-ray crystal data and structure refinement.
Empirical formula | C21 H22N4O2S2Sn |
Formula weight | 545.24 |
Temperature/ (K) | 100 (2) |
Wavelength/ (A) | 0.71073 |
Crystal system | Triclinic |
Space group | P-1 |
9.4663 (4) | |
14.7350 (7) | |
16.6374 (7) | |
94.871 (4) | |
96.434 (4) | |
90.793 (4) | |
Volume ( | 2297.1 (2) |
4 | |
Dc (Mg/m3) | 1.577 |
Absorption coefficient (mm-1) | 1.319 |
F(000) | 1096 |
Crystal size (mm) | |
Diffractometer | Kuma KM4CCD |
Theta range for data collection (°) | 3.14–36.65 |
Ranges of | |
Reflections collected | 35235 |
Independent reflections (Rint) | 18670 (0.0381) |
Completeness to 2 | 81.9% |
Data/parameters | 18670/541 |
Goodness-of-fit ( | 0.920 |
Final R1/wR2 indices [I | 0.0336/0.0768 |
Largest diff. peak/hole (e/Å3) | 2.090/ |
Crystallographic data, that is, atomic coordinates, thermal parameters, bond lengths, and bond angles (CCDC number 634270 for
The results of cytotoxic activity in vitro are expressed as IC50-the concentration of compound (in
The bands at 3555 and 3451 cm-1 are assigned to
1H and 13C resonances of the ligand H2L as well as of the complexes
In the 1H NMR spectra of (H2L)
The C=S resonance of the thiosemicarbazone moiety in the free ligand resonated at 178.0 ppm. All complexes showed an upfield shift of C7 peak in the order of
Crystals of complex
Bond lengths (Å) and angles (°) for complex 5.
Sn(1)–S(1) | 2.5141(5) | Sn(51)–S(51) | 2.5190(5) |
Sn(1)–O(1) | 2.087(2) | Sn(51)–O(51) | 2.088(2) |
Sn(1)–O(2) | 2.337(2) | Sn(51)–O(52) | 2.345(2) |
Sn(1)–N(3) | 2.251(2) | Sn(51)–N(53) | 2.262(2) |
Sn(1)–C(1) | 2.164(2) | Sn(51)–C(51) | 2.157(2) |
Sn(1)–C(7) | 2.149(2) | Sn(51)–C(57) | 2.151(2) |
S(1)–C(13) | 1.747(2) | S(51)–C(63) | 1.749(2) |
S(2)–O(2) | 1.528(2) | S(52)–O(52) | 1.528(2) |
S(2)–C(20) | 1.791(3) | S(52)–C(70) | 1.777(3) |
S(2)–C(21) | 1.789(2) | S(52)–C(71) | 1.787(3) |
O(1)–C(19) | 1.326(2) | O(51)–C(69) | 1.320(2) |
N(2)–N(3) | 1.380(2) | N(52)–N(53) | 1.375(2) |
S(1)–Sn(1)–O(1) | 156.25(4) | S(51)–Sn(51)–O(51) | 155.68(4) |
S(1)–Sn(1)–O(2) | 84.87(3) | S(51)–Sn(51)–O(52) | 83.23(3) |
S(1)–Sn(1)–N(3) | 77.37(4) | S(51)–Sn(51)–N(53) | 77.71(4) |
S(1)–Sn(1)–C(1) | 101.71(5) | S(51)–Sn(51)–C(51) | 100.07(5) |
S(1)–Sn(1)–C(7) | 95.51(5) | S(51)–Sn(51)–C(57) | 100.30(5) |
O(1)–Sn(1)–O(2) | 76.08(5) | O(51)–Sn(51)–O(52) | 77.25(5) |
O(1)–Sn(1)–N(3) | 84.11(5) | O(51)–Sn(51)–N(53) | 83.46(5) |
O(1)–Sn(1)–C(1) | 94.05(6) | O(51)–Sn(51)–C(51) | 95.98(6) |
O(1)–Sn(1)–C(7) | 97.14(6) | O(51)–Sn(51)–C(57) | 93.14(6) |
O(2)–Sn(1)–N(3) | 75.34(5) | O(52)–Sn(51)–N(53) | 75.65(5) |
O(2)–Sn(1)–C(1) | 165.59(6) | O(52)–Sn(51)–C(51) | 166.89(6) |
O(2)–Sn(1)–C(7) | 86.01(6) | O(52)–Sn(51)–C(57) | 87.15(6) |
N(3)–Sn(1)–C(1) | 93.44(6) | N(53)–Sn(51)–C(51) | 92.55(7) |
N(3)–Sn(1)–C(7) | 160.47(6) | N(53)–Sn(51)–C(57) | 162.80(6) |
C(1)–Sn(1)–C(7) | 105.87(7) | C(51)–Sn(51)–C(57) | 104.58(7) |
Molecular structure of the diorganotin complex
The C–S bond lengths 1.747(2), 1.749(2) Å for
The two monomers
C–H→
C–H(I) → | H–Cg | C–Cg | ∠C–H–Cg | ||
C(11)–H(11) [ | 2.71 | 3.5394 | 159 | ||
C(60)–H(60) [ | 2.66 | 3.4118 | 135 | ||
D | H | H | D | ∠D–H | |
N(1)–H(1A) | 2.13 | 3.005(2) | 165 | ||
N(1)–H(1B) | 2.28 | 3.065(2) | 150 | ||
N(1)–H(1B) | 2.55 | 3.124(2) | 124 | ||
N(51)–H(51A) | 2.16 | 2.993(3) | 168 | ||
N(51)–H(51B) | 2.24 | 3.013(2) | 152 | ||
C(8)–H(8) | 2.84 | 3.673(2) | 143 | ||
C(14)–H(14) | 2.50 | 3.442(2) | 175 | ||
C(58)–H(58) | 2.85 | 3.564(2) | 127 | ||
C(62)–H(62) | 2.55 | 3.132(2) | 118 | ||
C(64)–H(64) | 2.58 | 3.483(2) | 174 |
Arrangement of the intermolecular hydrogen bonds in
A view of the extended network of
The antiproliferative activity in vitro expressed as IC50 ± SD (
Complexes of
The antiproliferative activity of compounds is presented in Table
The antiproliferative activity in vitro of 1–4, expressed as as IC50 ± SD (
L929 | A549 | T24 | MCF7 | |
---|---|---|---|---|
9.04 ± 0.0 | ||||
M | 17.9 ± 0.86 | |||
B | 10.4 ± 0.41 | |||
P | 3.5 | |||
The ligand
The first author thanks I.K.Y. for a scholarship for her Ph.D. The authors also thank the NMR centre of ten University of Ioannina. This paper is dedicated to Professor Dr. N. Hadjiliadis for his contribution to the advancement of inorganic chemistry in Greece.