Chelation organotin compounds

D. Organotin Compounds Containing the C,N-Chelating o-Carboranylamino Ligand... 

The pentacoordinate organotin compounds 416a-c also contain a tridentate dianionic N,N,0-chelate ligand . The structure of 416c was determined by X-ray diffraction which conformed the rigid polycyclic structure proposed on the basis of H, B, C, and Sn NMR data in solution (S Sn —150.4 ppm) . In contrast, the dimethyltin compound 416a displays a fluxional structure in solution. 

II. Divalent Organotin Compounds Containing a C,Y-Chelating Ligand. . 247... 

Fig. S. Divalent organotin compounds stabilized by two C,N-chelating ligands.

Valuable information concerning the structures in solution of organotin compounds containing a C,N-chelating ligand is obtained from H, l3C, and 119Sn NMR spectroscopic studies. Furthermore, these studies provide sometimes detailed information on the fluxional processes that are operative in solutions of these compounds. It appears that the 119Sn chemical... 

A rather unusual series of compounds, which may be regarded as tetra-organotin compounds containing a potentially C,N-chelating ligand, are the triorganotin hydrides 37-39 shown in Fig. 11 (105,106). 

To increase the application time of polyurethane formulations, delayed catalysts are used, and this delay can be achieved by chelation of the organotin compound with mercaptans or dionate. Table 6.2.8... 

We have also initiated MUssbauer spectroscopic studies of photochemical reactions of inorganic and organometallic compounds (iron chelate complexes, iron carbonyl and organotin compounds) isolated in low temperature matrices. Such systems provide a complimentary approach to solid-phase photochemistry since the reaction mechanisms may be simplified by isolating the reactant molecules in inert matrices (light transmission through the reactant is also facilitated by diluting tlie colored reactant with a transparent medium). Furthermore, we have a hope for the possible outcome of such studies — their application to syntheses of novel species which may be unstable at ordinary temperatures, unless trapped in inert matrices. 

Pyridyl carboxylates tend to form oligomeric structures on coordination with organotin compounds. Generally, they show O-monodentate, N,0-chelate, 0,0- and N,0-bridging. 

The first examples of heteroleptic divalent organotin compounds authenticated by X-ray crystal structure determinations are [2-pyridylbis(tri-methylsilyl)methyl]tin chloride 12 and [2-pyridylbis(trimethylsilyl)methyl] bis(trimethylsilyl)amidotin 13, for which the structures are schematically shown in Fig. 8 (73). The distorted trigonal pyramidal coordination geometry of the tin center in these compounds may be a result of the formation of a four-membered chelate ring. 

TETRAVALENT ORGANOTIN COMPOUNDS CONTAINING A C,Y-CHELATING LIGAND... 

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