Synthesis and characterization of some diorganotin(IV) complexes of Schiff bases derived from a non‐protein amino acid. Crystal structures of {HO₂CC₆H₄[NC(H)}{C(CH₃)CH(CH₃)‐3‐OH]‐p} and its di‐n‐butyltin(IV) complex (ⁿBu₂Sn{O₂CC₆H₄[NC(H)}{C(CH₃)CH(CH₃)‐3‐OH]‐p}₂)

Abstract

Diorganotin(IV) complexes R 2 Sn(LH) 2 (R =Me

Synthesis and Structures of Two Triorganotin(IV) Polymers R3Sn{O2CC6H4[N=C(H)}{C(CH3)CH(CH3)-3-OH]-p} n (R = Me and Ph) Containing a 4-[(2Z)-(3-Hydroxy-1-methyl-2-butenylidene)amino] benzoic Acid Framework

“…In each symmetry-independent zwitterionic carboxylate ligand, the protonated N-atom forms an intramolecular hydrogen bond with the oxide O-atom of the same ligand to give a six-membered loop with a graph set motif [28] of S(6). The solid-state IR spectra of complexes 1 and 2 display a medium intensity band at around 3370 cm -1 which has been assigned to a νNH vibration, consistent with the complexes existing in the keto-enamine form, in accord with our earlier report [19]. This is also reflected in the crystal structures determined (vide supra).…”

“…This is also reflected in the crystal structures determined (vide supra). A strong sharp band due to the [ν asym (OCO)] stretching vibration of the free ligand (LHH') at 1699 cm -1 is shifted to ∼1636 cm -1 in 1 and 2 as a result of carboxylate coordination to the Sn atom [10,14,16,17,19]. [12,16,27,[31][32][33].…”

“…A usual common obstacle in the work is the synthesis of Schiff bases in the form of free acids and hence their sodium or potassium salt are frequently used for the reactions which are stable only for a short period. To overcome this difficulty, we recently synthesized a stable Schiff base in the form of the acid, 4-[(2Z)-(3-hydroxy-1-methyl-2-butenylidene)amino]benzoic acid (LHH'), which has been characterized crystallographically and some of its organotin(IV) complexes have been reported [19]. As a continuation of our previous work in this area, we report the synthesis and characterization of two new polymers viz., [Me 3 Sn(LH)] n (1) and [Ph 3 Sn(LH)] n (2) containing the ligand LH bridging two triorganotin moieties through both carboxylate and hydroxide groups.…”

Synthesis, spectral analysis and in vitro cytotoxicity of diorganotin (IV) complexes derived from indole‐3‐butyric hydrazide

“…The tautomerization of Schiff base ligands and coordination of enolic oxygen with the tin (IV) metal center was suggested in the IR spectra but the confirmation was given by the disappearance of O=C-NH signal in proton NMR. [50,51] The signal at δ 8.11-9.39 ppm due to azomethine proton (N=CH) got shifted downfield on complexation due to the donation of electron density from azomethine nitrogen to tin (IV) metal atom. The 3 J( 119 Sn-1 H) coupling gives tin satellite peaks with the azomethine proton signals due to coupling of azomethine proton with tin metal and comes in the range of 43-48 Hz, confirms the coordination of nitrogen with tin (IV) metal and formation of Sn-N bond.…”

Structural diversity among some dialkyltin(IV) benzoate and related derivatives

“…This zwitterionic nature has caused some delocalization of the bonding electrons in the alkyl chain, as seen by the bond lengths in Table 4. The molecular structure of the analogous dibutyltin(IV) complex with the same substituted 4-aminobenzoate ligand (Basu Baul et al, 2008) is similar to that of (III), albeit without the additional water ligand. The coordination geometry itself is thus more akin to the skew-trapezoidal bipyramidal arrangement of (I) and (II), with the more asymmetric carboxylate coordination and less linear C-Sn-C angle.…”