TRIPHENYLSTANNATE DERIVATIVES OF CARBOXYLIC-ACIDS - CRYSTAL-STRUCTURES OF PYRIDYL-2-AMINO-2-PYRIDINIUM BIS(TRIFLUOROACETATO)TRIPHENYLSTANNATE AND PYRIDYL-2-AMINO-2-PYRIDINIUM IFLUOROACETATO)(TRIFLUOROACETATO)TRIPHENYLSTANNATE

The crystal structure of pyridyl-2-amino-2-pyridinium bis(trifluoroace tato)triphenylstannate consists of pyridinium cations and five-coordin ate trans-C3SnO2 trigonal bipyramidal stannate [Sigma(C-Sn-C) = 360.0( 6)degrees, O-Sn-O = 178.6(2)degrees] anions. The stannate anions are l inked through the carbonyl oxygen atoms to the amino and pyridinium ni trogen atoms of adjacent cations by hydrogen bonds to form helical cha ins that run parallel to the b-axis of the unit cell. The tin atom in pyridyl-2-amino-2-pyridinium fluoroacetato)(trifluoroacetato)-tripheny lstannate also shows trans-C3SnO2 trigonal bipyramidal [Sigma(C-Sa-C) = 359.6(4)degrees, O-Sn-O propagate linearly along a body diagonal: Pa irs of the chains are racemic in both compounds. The latter stannate i s the first example of a triorganostannate having two different carbox ylato groups bonded to tin.