The Biological Activity of Organotin Free Essay Example

A lot of methods have been used for synthesizing the organic and inorganic tin complexes due to their synthetic and biological applications1. Tin (II) and tin (IV) organometallic compounds are having various geometries. Organotin (IV) derivatives form complexes with various Lewis bases ligands containing oxygen or nitrogen2. Pyridine establishes a key example of a monodentate and 1, 10-phenanthroline is a bidentate ligand containing nitrogen as an electron donor. The pyridine or 1, 10-phenanthroline ligand is complexed with metal atoms by either its nitrogen lone electron pair (?? complexation) or its aromatic ??electron cloud (??complexation).

The organotin(IV) compounds show strong biological activity . Even at low concentration, the number of organotin(IV) compounds are toxic. Based on the number and nature of the organic groups bound to the central {Sn} atom3, the biological activity can be determined. The [R3Sn(IV)]+ and [Ar3Sn(IV)]+ derivatives employ powerful toxic action on the central nervous system4.

In coordination chemistry, 4-N, N-Dimethyl aminopyridine and 1, 10-Phenanthroline and its derivatives are versatile ligands because metal complexes of these ligands are having many analytical applications5.

They implicate dissimilar geometry in the complexation with several metals in coordination properities6. Transition metal complexes of 4-N, N-dimethyl aminopyridine and 1, 10-phenanthroline and its substitution have shown as in vitro anticancer agents against selected cancer cell lines7. Platinum and ruthenium-based drugs are mostly used for cancer treatment. But they are not so good for all stages of cancer8 Hence the synthesis of diorganotin dihalide and triorgano tin halide complexes are aimed to stimulate new metal-based drug treatments against a wide range of diseases.

Here, the report is aimed on the synthesis of new triorganotin(IV) and diorganotin (IV) halide complexes synthesized by the reaction of (methyl or m- or p- substituted benzyl)2SnX2 with 4-N,N-dimethylamino pyridine and 1, 10-Phenanthroline and its derivatives, in which Sn is capable of making extended coordination with the ligands.. Moreover, theoretical and biological studies of the products were also supported out in this research work. The investigations such as FT-IR, FT-Raman, multinuclear NMR spectra (1H, 13C and 119Sn) and X-ray diffraction of the organotin(IV) complexes reveal the arrangements of the atoms in the products which exhibit that the Sn atom is coordinated through nitrogen atoms ligands.

The scope of the research work:

• The biological activity of organotin (IV) complexes is associated to the number of Sn-C and Sn-N bonds and the type of aryl or alkyl and groups in the organotin(IV) halides9
• The cytotoxicity or anti-tumour activities of organotin (IV) derivatives shows a important requirement in medicinal chemistry
• A large number of organotin (IV) halides have been analysed for their in vitro activity against a large variety of tumour cell lines. They have been identified as effective or better than traditionally used anticancer drugs such as cis-platin10.
• The various synthetic routes of organotin(IV) halides with monodentate and bidentate N donor ligands are of countless interest for the development of anticancer, antitumour, antibacterial, antiviral, antifungal drugs.

Methodology:

•  Diorganotin compounds have been synthesized from tin powder in zero valent state and respective benzyl halides under reflux conditions. 4-N, N-dimethyl aminopyridine and 1,10-Phenanthroline and its derivatives have been slowly added straight away to the reaction mixture
•  The solvents are used in an appropriate amount with reaction mixtures and it is allowed for stirring and heating to carry out the reaction at room temperature. After the reaction is over, the excess of solvents are removed under reduced pressure in a vacuum
•  The vapours of different are diffused for the crystallization of the complexes.
•  The new complexes were investigated by FT-IR, FT-Raman, 1H NMR, 13C NMR, 119Sn NMR, and X-ray analysis for the structure of complexes.
•  By using DFT calculation (Gaussian 09W package)bond distances and frequencies of the complexes are theoretically calculated and they were compared with the corresponding experimental frequencies of FT-IR and Raman spectra.
•  Also, cytotoxic activities are carried out for all the complexes and detailed in a separate chapter
•  HOMO-LUMO and Electrostatic potential surface maps have been discussed.

Chapter-I: It deals about various synthetic routes of organotin compounds with nitrogen donor ligands like 4-N, N-dimethyl aminopyridine and 1, 10-phenanthroline and its derivatives. Furthermore, a large number of tin complexes are taken to account for characterization of tin complexes using FT-IR, multiple NMR and single crystal XRD analysis with certain references.

Chapter II: Experimental procedure and theoretical methods are considered to explain the coordination linkages between ligands with N, S, O, etc with the organotin compounds. Furthermore, certain tin complexes possess effective biological activities like mosquitocidal, anticancer, antimalarial, antibacterial, etc. Cytotoxic characterizations of some tin complexes are taken to research.

Chapter III: Complexes such as (Chloro) (trimethyl) (4-N,N-dimethyl aminopyridine) tin(IV) and Di(p-chlorobenzyl) (di-4-N,N-dimethyl aminopyridine)] (dichloro) tin(IV) were synthesized and confirmed through usual analysis. Optimized geometrical parameters, chemical characterizations were discussed.

Chapter IV: This chapter deals with the synthesis of Di (m-bromobenzyl) (dibromo) (1,10-

phenanthroline) tin(IV) and Di (m- chlorobenzyl) (dibromo) (1,10-phenanthroline) tin(IV) complexes. The theoretical calculations are carried out using DFT methods.

Chapter V: The synthesis and studies of Di (m-bromobenzyl) (dibromo) (4,7- dimethyl-1,10-phenanthroline) tin(IV) and Di (m- chlorobenzyl) (dibromo) (4,7- dimethyl-1,10-phenanthroline) tin(IV) complexes are discussed in this chapter. Physical parameters, chemical characterizations were concentrated.

Chapter VI: The synthesis and studies of Di (m-bromobenzyl) (dibromo) (4,7- diphenyl-1,10-phenanthroline) tin(IV) and Di (m- chlorobenzyl) (dibromo) (4,7- diphenyl-1,10-phenanthroline) tin(IV) complexes complexes were carried out in this chapter. HOMO-LUMO and Electrostatic potential surface maps have been discussed.

Chapter VII: In this chapter, synthesis of (Di (p-methylbenzyl) (dibromo) (4,7- diphenyl-1,10-phenanthroline) tin(IV) and Di (m- chlorobenzyl) (dichloro) (4,7- diphenyl-1,10-phenanthroline) tin(IV) complexes are examined by conventional analysis. Optimized geometrical parameters, chemical characterizations were considered.

Chapter VIII: Cytotoxicity of complexes is analysed. Nowadays, cisplatin is used as an anticancer drug for several types of cancers in the human body as a metal-based drug. In general, Organotin complexes are also found to be similar to cis-platin and reduce side effects.

Conclusion

As an extension of synthesis of organotin complexes, the reactions had been carried out between substituted triorgano tin halide compounds with 4-N, N-dimethyl aminopyridine under ordinary reaction conditions and diorganotin halide compounds with 1, 10- Phenanthroline or 4, 7-substituted-1, 10-phenanthroline under ordinary reaction conditions. The coordination of ligands with triorgano tin halides and diorgano tin dihalides has been explored by using FT-IR, FT-Raman, 1H, 13C and 119Sn NMR spectra and X-ray diffraction techniques. The cytotoxic activities of these complexes have been analyzed. These complexes have been studied by DFT methods in order to compare the experimental spectral values and are in good agreement with theoretical values.