Synthesis and spectroscopic characterization of new adducts of diorganotin(IV) dichlorides with an asymmetric schiff base ligand

Synthesis and characterization of some new di- and triorganotin(IV) complexes of Schiff base derived from o-vanillin and acetazolamide using microwaves

“…The signal at δ 9.90 ppm in the case of ligand assigned to phenolic (OϪH) proton disappears in the spectra of complexes. It confirms that the Schiff base coordinates through phenolic oxygen by the loss of proton as water (Sedaghat and Menati, 2004). A strong peak at δ 3.7 ppm has been assigned to amide (NϪH) proton, and the corresponding peak is observed in the complexes, although slightly shifted in position, indicating that amide proton is not lost during complexation.…”

Synthesis, structural characterization, biological activity and thermal study of tri‐ and diorganotin(IV) complexes of Schiff base derived from 2‐aminomethylbenzimidazole

“…The absence of such a signal in all of the organotin(IV) complexes suggests the deprotonation of the phenolic OH of Schiff base on complexation. [16,20,28] In the 1 H NMR spectra of the complexes, a signal at δ 8.63 ± 0.04 ppm for triorganotin(IV) complexes and δ 8.72 ± 0.09 ppm for diorganotin(IV) complexes has been assigned to the azomethine proton (-CH N-). It appears at low frequency in all of the studied complexes as compared with the corresponding signal of uncoordinated Schiff base (8.69 ppm in CD 3 OD/8.96 ppm in DMSO-d 6 ), indicating thereby the coordination of the ligand to the tin via azomethine nitrogen (Sn ← N).…”

Tin(IV) Schiff base complexes: Synthesis, thermodynamic and anti bacterial investigation, experimental and theoretical studies

“…The 119 Sn NMR spectra of all titled complexes [Me 2 SnCl 2 .H 2 L [1][2][3][4][5] give sharp signals at -166.65, -163.55, -161.43, -161.76, -168.93 ppm, respectively, which is indicative of five coordinated environment around the tin atom. Thus on the basis of the above evidences it is suggested that the geometry of the resulting tin complexes be characterized as trigonal bipyramidal [21,29,30]. The proposed structures of newly synthesized complexes are shown in Figure 1.…”

“…Weak broad absorption bands appearing in the range of 2800-2900 cm -1 for the free Schiff base ligands are assigned to (O-H) and (N-H) overlapping with the (C-H) [16]. These bands are observed to shift slightly to higher frequency due to the coordination of phenolic oxygen atom with tin and changes in hydrogen bonding [21]. The strong bands at 1622-1649 cm -1 , which can be attributed to (C=N) stretching frequency on Schiff base ligands [16].…”