Vitamin B₁₂Model Complexes: Synthesis and Characterization of Thiocyanato Cobaloximes and Thiocyanato Bridged Dicobaloximes of O-donor Ligands: DNA Binding and Antimicrobial Activity

Abstract

요약. L이 urea, acetamide, semicrabazide, formamide 인 thiocyanato (L) Cobaloxime 착물을 합성하고 특성을 규명하였다. 주제어: Thiocyanato 리간드 cobaloximes, Thiocyanato 로 연결된 dicobaloximes, 항균 활성, DNA 결합 Thiocyanato(L)cobaloximes (SCNCo(DH)2(L))과 benzyl (aquo) cobaloxime PhCH2Co(DH)2(OH2)를 반응시켜 일반 분자식 ABSTRACT.Complexes of thiocyanato(L)cobaloximes where L is urea, acetamide, semicrabazide and formamide were synthesized and characterized. The reaction of thiocyanato (L) cobaloximes (SCNCo(DH)2(L)) with benzyl (aquo) cobaloxime PhCH2Co (DH)2(OH2) was found to produce a series of thiocyanato bridged dicobaloximes of a general formula of PhCH2Co(DH)2SCNCo (DH2)(L). Evidence for formulation as dicobaloximes containing thiocyanato ligand bridges was obtained from infrared data which show 20 -45 cm -1 increase in νCN upon formation of the dicobaloxime from the corresponding terminal thiocyanocobaloxime (SCNCo(DH)2(L)). Further characterization of these two series was done on the basis of ( 1 H, 13 C)NMR, LCMS and elemental analysis. Anti-microbial activity of thiocyanato(L)cobaloximes and thiocyanato bridged dicobaloximes were screened against E. Coli. The DNA-binding behaviors of both monomers and dimers were investigated by spectroscopic methods and viscosity measurements. The results indicated that the dimer complexes bind with calf-thymus DNA in an intercalative mode via the terminal benzyl ring into the base pairs of DNA. It was observed that the monomer complexes did not interact with DNA. Fluorescence spectra for the interaction between thiocyanato bridged dicobaloximes and DNA were also studied.

Transition metal complexes of a hydrazone–oxime ligand containing the isonicotinoyl moiety: Synthesis, characterization and microbicide activities

“…This type of coordination was proposed from the following evidence: The negative shift of the ν(OH) group band indicates the participation of oxime hydroxyl group. At the same time there is a positive shift of the NO band to the regions 1037–1064 cm −1 A negative shift in the position and intensity of imine and oxime C―N groups by 14–37 and 51–76 cm −1 , respectively …”

“…This way of chelation was indicated by the following: The absence of ν(OH) band demonstrating the participation of the oxime hydroxyl group via loss of the hydrogen atom. At the same time there is a positive shift of the NO band to the regions 1134–1156 cm −1 A negative shift in the position and intensity of imine and oxime C―N groups by 11–41 and 12–61 cm −1 , respectively. A negative shift in the position and intensity of the carbonyl group by 11–64 cm −1 . The appearance of bands in the 519–632 and 442–593 cm −1 ranges for complexes 2 , 5–7 , 10 and 12 could be assigned to ν(M―O) and ν(M←N), respectively …”

“…At the same time there is a positive shift of the NO band to the regions 1037–1064 cm −1 A negative shift in the position and intensity of imine and oxime C―N groups by 14–37 and 51–76 cm −1 , respectively A negative shift in the position and intensity of the carbonyl group by 5–37 cm −1 . Bands in the 582–590 and 427–510 cm −1 ranges for complexes 3 , 4 and 13 can be assigned to ν(M←O) and ν(M←N), respectively …”

“…At the same time there is a positive shift of the NO band to 1055 cm −1 A negative shift in the position and intensity of imine and oxime C―N groups which appear at 1607 and 1570 cm −1 , respectively The absence of the band assigned to ν(NH) and ν(C―O) of hydrazide moiety pointed out that the carbonyl oxygen atoms take part in the bonding to the uranyl(II) ions in enolic form.…”

Preparation, characterization and Microbicide activities of N'-((3-(hydroxyimino)butan-2-ylidene)-2-(phenylamino)acetohydrazide and its complexes

“…These findings suggest the bonding of the ligand the metal ions takes a monobasic tridentate mode via de-protonation of an oxime moiety, azomethine and carbonyl groups. The participation of the OH group of the oxime via loss of the hydrogen atom is accompanied by a strengthening in NO double bond, which is declared in the positive shift of the two NO bands to the regions (1148-1175), (1037-1096) cm -1 [49,54]. The spectra of complexes (6) and (7) show similar patterns except the still presence of the OH group of the oxime, although this band was subjected to shifting by a (10-13 cm -1 ), which suggested the chelating of the ligand to metal ions in a neutral tridentate mode in these two complexes (Fig.…”