Comparative study of structure: activity relationship of di and triorganotin (IV) complexes of monomethyl glutarate

Abstract

Uma série de complexos di-e tri-organoestanho(IV) de metilglutarato foram sintetizados e caracterizados por espectroscopia de RMN de 1 H, 13 C e 119 Sn, no infravermelho e Mössbauer de 119 Sn. Baseado nestas técnicas propõe-se que o ligante se encontra ligado ao estanho através do oxigênio da carbonila. Os dados revelam também que os complexos diorganoestanho(IV) são hexacoordenados, com geometria octaedrica, enquanto que os complexos triorganoestanho(IV) são pentacoordenados e possuem geometria bipiramidal trigonal. A avaliação biológica contra vários microorganismos indica que os complexos diorganoestanho(IV) são menos ativos que os triorganoestanho(IV).A series of di and triorganotin(IV) complexes of monomethyl glutarate have been synthesized and characterized through 1 H 13 C 119 Sn NMR, FT-IR and 119 Sn Mössbauer spectroscopy. On the basis of these techniques, it is proposed that the ligand molecule is bound to the tin atom through the carbonyl oxygen. The data reveal that diorganotin(IV) complexes exhibit hexa-coordination with octahedral geometry, while triorganotin(IV) complexes have penta-coordination with trigonal bipyramidal geometry. Biological evaluation against various microorganisms indicate that diorganotin(IV) complexes are less active than the triorganotin(IV) complexes.Keywords: organotin(IV), monomethyl glutarate, biological activity IntroductionOrganotin(IV) complexes have wide applications as catalysts, stabilizers as biocides, as antifouling agents, and for wood preservers. [1][2][3][4][5][6][7][8][9][10] In recent years, investigations have been carried out to test their antitumor activity, and it has been observed that indeed several di and triorganotin(IV) species were found to be active against various types of cancer. 11-13. Biological activity of organotin complexes is believed to be independent on the structure of molecule and coordination number of the metal. [4][5][6] It has also been noted that many di and triorganotin(IV) carboxylates display interesting anti tumor activities. [13][14][15][16][17][18][19][20] However the solubility of di and tri-organotin(IV) carboxylates in water and water-ethanol is poor, therefore many organotin(IV) complexes with carboxylate ligands containing polar subsitituents (hydroxo and oxo groups) have been prepared and studied. [13][14][15][16][17][18][19][20] In a previous paper we described the synthesis of organotin(IV) complexes of maleimidoacetic acid. 21 In the present work we report the synthesis, spectroscopic characterization, antibacterial and various biological activities of a series of di and triorganotin(IV) complexes of monomethyl glutarate. ExperimentalAll the di and triorganotin(IV) compounds except for dibenzyl and tribenzyl tin chlorides were purchased from Fluka and were used as such. Di and tribenzyltin chlorides were synthesized from the literature method. 22 All the reactions were carried out under anhydrous and oxygen free nitrogen atmosphere. The solvents used were dried before use according to the literature method. 23 The...

Synthesis, larvicidal, QSAR and structural studies of some triorganotin 2,2,3,3‐tetramethylcyclopropanecarboxylates

“…The 1 J( 119 Sn-13 C) coupling constants have been used to infer the coordination number of the tin atom 2,22 in organotin compounds. As can be seen in Table 4 …”

Heptacoordinate Tin(IV) Compounds Derived from Pyridine Schiff Bases: Synthesis, Characterization, in Vitro Cytotoxicity, Anti-inflammatory and Antioxidant Activity

“…3) Among the most studied organotin(IV) complexes a special emphasis has been placed on the study of carboxylates as potential metallotherapeutic drugs, 4) however, a wide spectrum of biological activities such as anti-microbial, [5][6][7][8][9][10] anti-inflammatory, [11][12][13][14][15] anti-fungal, 14) cardiovascular, 5,10,16,17) anti-tuberculosis 18,19) and biocide among others remains a subject of intense study. 20) Schiff bases are of paramount importance as ligands in metal coordination chemistry as they form stable complexes with most of transition metals.…”

Synthesis, Characterization, Spectral Studies, Antibacterial Evaluation, Thermodynamics and DFT Calculations of Dimethyltin(IV) Dichloride Schiff Base

“…It can be noted that the compounds with phenyl groups showed the greatest inhibitory effect on one or more types of bacteria as compared to Me and CF 3 group in the same position. 53 me direction. The withdrawing functional groups (CF 3 ) and (Ph) make the Schiff base as a poor donor ligand and decrease the stability of complexes while the electron donor group (CH 3 ) increasing the stability because they leads to increase the donor ability of Schiff base ligands.…”