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Innovative Medicines & Omics Synthesis and docking of diorganotin (IV) chelates

Table 2. Synthetic, physical, and elemental data of the diorganotin (IV) complexes, with calculated values given in parentheses
No. Compound Melting Yield (%) Molecular weight (g/mol) Sodium chloride filtered (g) Elemental analysis (%)
point (°C) analyzed (calculated) (calculated) (calculated)
Tin (Sn) Sulfur (S)
1 Chelate-1 110 78 470.00 (470.18) 0.19 (0.20) 25.18 (25.24) 6.75 (6.82)
2 Chelate-2 130 68 482.00 (484.18) 0.22 (0.24) 24.48 (24.51) 6.58 (6.62)
3 Chelate-3 108 72 530.00 (532.23) 0.35 (0.36) 22.38 (22.30) 5.95 (6.02)
4 Chelate-4 112 79 570.00 (566.67) 0.38 (0.39) 20.86 (20.95) 5.63 (5.66)

1
to –OH and > NH groups, disappeared in the spectra of Table 3. The H nuclear magnetic resonance spectral data of
the corresponding organotin (IV) chelates. In addition, organotin (IV) complexes (in δ ppm)
the appearance of a new band in the 1,625 – 1,645 cm Chelate Ring Ring/terminal Terminal Sn‑R 2 J(Sn‑H)
−1
range indicates the presence of the stretching frequency methyl C H /C H Cl protons
4
5
6
6
(ν) > C=N–group. In addition, a band detected in the thiophenol >CH –CH
33
−1
13
range of 660 – 625 cm is assigned to ν S–oxygen (O) ring 2 3
(asymmetric ν). The presence of the Sn-S bond is supported Chelate-1 2.42 bs 6.54 – 7.99 m - 2.42 bs 0.83 bs 100.59 Hz
by the appearance of the ν Sn-S absorption band in the Chelate-2 2.45 s 6.90 – 8.28 m 2.86 q 1.05 t 1.05 bs -
6,7
region 422 – 402 cm . A weak absorption band of low Chelate-3 1.88 s 6.84 – 8.24 m - - 1.08 s -
−1
intensity in the region 456 – 425 cm is associated with Chelate-4 1.97 s 7.26 – 8.22 m - - 1.45 s -
−1
Sn–N bonds. The presence of these bands indicates the
2
formation of Sn–O, Sn–S, and Sn–N bonds, supporting Abbreviations: bs: Broad singlet; q: Quartet; R: functional group;
s: Singlet; t: Triplet.
the bifunctional tridentate coordination mode of the Schiff
bases in the organotin (IV) chelates.
3.1.2. H NMR
1
The H NMR spectra were recorded in CDCl /DMSO-d
1
6
3
using TMS as the internal standard. A summary of the
chemical shifts observed is presented in Table 3. The broad
signal at δ 4.96 ppm, attributed to >NH/–SH protons in
the Schiff bases, is absent in the spectra of the organotin
3
(IV) chelates, indicating deprotonation of these functional
groups. The signal for ring methyl protons is observed at δ
1.69 – 2.46 ppm as a singlet.
No significant shifts were detected in their position
compared with their positions in parent ligands. In
Chelate-1, the signal for the terminal proton appears at δ
2.42 ppm as a broad singlet. In contrast, for Chelate-2 and
Chelate-4, the terminal protons resonate as a quartet at δ
2.78 – 2.86 ppm, corresponding to > CH protons, and as
2
a triplet at δ 1.05 – 1.11 ppm, attributed to –CH protons.
3
The methyl protons bonded to the Sn atom are observed as
a singlet in the range of δ 0.83 – 1.45 ppm, while the butyl
protons attached to the Sn atom exhibit a complex pattern
between δ 0.61 and 2.48 ppm. The value of Sn-hydrogen
(H) J coupling, J(Sn-H) for Chelate-1 was found to be
2
100.59 Hz. The proton signals from the phenyl ring Figure 1. Synthetic pathway for the preparation of diorganotin (IV)
34
(C H /C H ), as well as those from the thiophenol ring, chelates (Chelate-1 to Chelate-4)
6
5
4
6
are merged, and the aromatic protons appear as a complex
13
pattern in the range δ 6.38 – 8.33 ppm. Thus, H NMR 3.1.3. C NMR
1
spectral studies also support the bifunctional tridentate The C NMR spectra of the complexes were obtained
13
nature of the ligand. in chloroform using TMS as the reference standard. The
Volume 2 Issue 3 (2025) 71 doi: 10.36922/IMO025140019