Triphenylsilicon(IV) Derivatives of Schiff Bases Derived from Amino Acids

Synthesis, Characteristic Spectral Studies and in Vitro Antimicrobial Activity of Organosilicon(IV) Complexes of N-(2-Hydroxynaphthalidene)-Amino Acid Schiff Bases

“…Two sharp bands in the regions 1572-1634 and 509-583 cm −1 are observed and assigned to the ν(C N) azomethine 18,19 and ν(Si ← N) 22,23 frequencies, respectively, indicating the coordination of the ligand to the central silicon atom through the azomethine nitrogen. In the spectra of the complexes two sharp bands are observed at 1629 ± 5 and 1389 ± 19 cm −1 and are assigned to ν as (COO) and ν s (COO) respectively.…”

“…18,19,22,23 Whereas the infrared spectra of triorganosilicon(IV) derivatives of monosodium salts of Schiff bases derived from 2-hydroxy-1-naphthaldehyde and sodium salts of the amino acides exhibit a band in the 3300-3200 cm −1 region, which could be due to phenolic OH stretching vibrations. This suggests that the phenolic oxygen in R 3 SiHL complexes is not involved in coordination.…”

“…37 Furthermore, the separation between the ν as (COO) and ν s (COO) is about 248 ± 26 cm −1 , indicating the covalent nature of the metal-oxygen bond. 18,19,22 Ionic bonding, bridging, or chelation can therefore be excluded, and it must be assumed that the carboxyl groups bind silicon unidentately. 18,19,22 The sharp bands at 830 ± 30 and 635 ± 35 cm −1 in the spectra of the complexes have been assigned to ν as (Si O) and ν s (Si O) respectively.…”

“…18,19,22 Ionic bonding, bridging, or chelation can therefore be excluded, and it must be assumed that the carboxyl groups bind silicon unidentately. 18,19,22 The sharp bands at 830 ± 30 and 635 ± 35 cm −1 in the spectra of the complexes have been assigned to ν as (Si O) and ν s (Si O) respectively. [7][8][9]22,23 Five-coordinate complexes of the type R 3 Si(NO) (where NO = coordinating site of the monoanions of H 2 L 1 to H 2 L 5 ) may assume either of the three trigonal-bipyramidal arrangements (A), (B), and (C) of C s , C 3v and C s symmetry respectively (Figure 4).…”

“…18,19,22 The sharp bands at 830 ± 30 and 635 ± 35 cm −1 in the spectra of the complexes have been assigned to ν as (Si O) and ν s (Si O) respectively. [7][8][9]22,23 Five-coordinate complexes of the type R 3 Si(NO) (where NO = coordinating site of the monoanions of H 2 L 1 to H 2 L 5 ) may assume either of the three trigonal-bipyramidal arrangements (A), (B), and (C) of C s , C 3v and C s symmetry respectively (Figure 4). The IR spectra of trimethylsilicon(IV) derivatives show two bands around 1470 ± 10 cm −1 and 1245 ± 13 cm −1 , which have been assigned to the asymmetric and symmetric deformation modes of CH 3 Si respectively.…”