Structural and spectral studies of N-(3-hydroxypyridine-2-yl)salicylideneimine and N-(3-hydroxypyridine-2-yl)-5-bromosalicylideneimine and their dimethyltin(IV) complexes

Abstract

Abstract

Synthesis and characterization of diorganotin(IV) complexes of tridentate Schiff bases: crystal structure of [N-(3-hydroxypyridine-2-yl)-5-chlorosalicylideneiminato]dimethyltin(IV)

“…As the total sum of equatorial angles is exactly 360°, the Sn atom lies in the C13-C14-N1 plane. These geometric results are in agreement with the results of similar tin(IV) complexes [15,27,28,[31][32][33][34][35][36]. The distortion is probably due to the rigidity of chelate rings, and facilitated by the large covalent radius of tin(IV).…”

“…The HC=N bond length in 3a is comparable to the literature values found for similar Sn(IV) complexes [27,28] and this parameter appears to be more or less related to the inductive electronegativity [40,41] of the substituent, X, on the salicylaldehyde ring ( Table 3). As is evident from Table 3, the higher the electronegativity of X, the longer HC=N bond length.…”

“…This is in agreement with the literature values [27,28,[42][43][44]. The Schiff bases are apparently in the phenol-imine tautomeric form as the azomethine proton in a quinoid structure is known to exhibit a three-bond coupling to the NH proton [42][43][44][45][46][47][48].…”

“…As a continuation of our previous work in this field [27,28], we have prepared four different penta coordinated organotin(IV) Schiff base complexes in which the metal was coordinated to tridentate ligands containing nitrogen and oxygen donors. Here we report the synthesis and characterization of potentially tridentate ONOdonor Schiff bases and their dimethyltin(IV) complexes.…”

Synthesis, structural, and spectral studies of N,N′-bis- (5-methylsalicylidene)-2,2′-diamino-4-4′-di-(trifloromethyl)-diphenyl disulfide

“…The single proton giving a singlet at 8.68 ppm may be assigned to the azomethine proton. Also, the signal of the CH=N proton shows no CH-NH coupling and indicates the predominance of the phenol-imine tautomer form of the Schiff base [24,25]. The signals at 7.46 and 7.42 ppm are assigned to the H(3,3 ) and H(5,5 ), respectively.…”