Syntheses, crystal structures and coordination modes of tri- and di-organotin derivatives with 2-mercapto-4-methylpyrimidine

Synthesis and Structural Characterisation of Diorganotin(IV) and Diphenyllead(IV) Complexes of Pyrimidine‐2‐thionate Derivatives

“…These values are similar to those found in other hexacoordinate diorganotin(IV) compounds with anionic heterocyclic thionate N,S-chelate ligands, which have values in the range 2.4476(10)-2.503(2) Å. [22,[42][43][44][45][46] [47] but are rather longer than those found in other complexes containing Sn-N bonds {e.g., 2.271(9) and 2.256(9) Å in [Cl 2 Sn(pyS) 2 ]}. [48] However, the values obtained for 1, 2, 5 and 6 are in the range found in the aforementioned [R 2 Sn(chelate…”

“…These values are within the range reported for other complexes of diphenyl-or dimethyltin(IV) with pyrimidine or pyrimidine-2-thionate ligands with the same coordination number. [22,47,65] In the spectra of the tBu 2 Sn derivatives, the values of the 119 Sn chemical shift are δ = -32.1 ppm for 3 and δ = -4.8 ppm for 6. These seem to indicate that the complexes have a lower coordination number (tetracoordination) in CDCl 3 solution than in the solid state.…”

“…The 2 J1 H, 119 Sn and 2 J1 H, 117 Sn coupling constants are 74 and 72 Hz, respectively, and these values are similar to those found in other compounds containing the Me 2 Sn fragment. [22,63] These 2 J coupling constant values can be used to estimate the Me-Sn-Me angle. [64] The values calculated for these angles are 123.9°and 121.8°for 1 and 4, respectively, and are very similar to one another and also to that found in the solid state for 1 by X-ray diffraction.…”

“…[15,16] In addition, organotin complexes have been studied more recently in terms of their pharmacological and antitumour activity. [17][18][19][20][21][22] As a continuation of our studies into the coordination chemistry of sterically hindered heterocyclic thiones, [23] we report here the synthesis and characterisation of diorganotin(IV) and diphenyllead(IV) complexes with 4-(trifluoromethyl)pyrimidine-2-thione and 6-methyl-4-(trifluoromethyl)-pyrimidine-2-thione ligands, the structures of which are shown in Scheme 1. These ligands, besides having solubilising and bulky groups, belong to one of the most versatile types of sulfur ligand in terms of coordination modes.…”

Synthesis and Structural Studies of Organotin(IV) and Organolead(IV) Thiophene‐2‐thiocarboxylate

“…The peak at δ = -190.10 ppm in the spectrum of 1c indicates a five-coordinate environment around the tin center. [11] 119 Sn signals for four-coordinate compounds are observed in the range of δ = +200 to -60 ppm. [11] Signals at δ = -69.68 and -77.71 ppm, respectively, in the cases of 1a and 1b indicate higher (Ͼ4) coordination numbers around the tin atom, which is possibly due to the existence of weak Sn-O bonds (the primary bonding of ligands is through the sulfur atoms).…”