DIBUTYLTIN DERIVATIVES OF 2,6-PYRIDINEDICARBOXYLIC ACIDS - CRYSTAL-STRUCTURES OF BIS(DIISOPROPYLAMMONIUM) RIS(2,6-PYRIDINEDICARBOXYLATO)BIS(DIBUTYLSTANNATE) TRIHYDRATE AND BIS(DIISOPROPYLAMMONIUM) IBUTYLSTANNYL(2,6-PYRIDINE-DICARBOXYLATO-4-OLATE)]

Dibutytlin oxide condenses with diisopropylammonium hydrogen 2,6-pyrid inedicarboxylate to form bis (diisopropyl ammonium) ris(2,6-pyridinedi carboxylato)bis(dibutylstannate) trihydrate, whose crystal structure c onsists of a three-dimensional hydrogen-bonded framework of ammonium c ations, stannate anions and water molecules. In the dianion, the carbo xyl -CO2 groups of the central 2,6-pyridinedicarboxylato member are ea ch chelating an O,N,O-dibutyl(2,6-pyridinedicarboxylato)tin molecule f lanking it; one molecule has its C2Sn skeleton in an almost linear ali gnment [C-Sn-C 173.8(6)degrees; Sn-O 2.423(8) Angstrom, 2.457(9) Angst rom] whereas the other has a bent C2Sn skeleton [C-Sn-C 158.0(7)degree s] arising from anisobidentate chelation [Sn-O 2.303(7) Angstrom, 2.78 5(8) Angstrom]. Their tin atoms are seven-coordinate in trans-C2SnNO4 pentagonal bipyramidal geometries. Dibutyltin oxide reacts with diisop ropylammonium hydrogen 4-hydroxy-2,6-pyridinedicarboxylate to yield ce ntrosymmetric bis(diisopropylammonium) dibutylstanny(2,6-pyridinedicar boxylato-4-olate)]. The water-coordinated tin atom [Sn-O-water 2.409(3 ) Angstrom] in the adibutylstanny(2,6-pyridinedicarboxylato-4-olate)] dianion, whose negative charges reside on the 4-substituent oxygen ato ms, is also seven coordinate [C-Sn-C C 159.6(2)degrees]. The dianions are linked to adjacent dianions through the diisopropylammonium counte rions [N ... O-esteryl 2.954(4) Angstrom, N ... O-hydroxyl 2.719(5) An gstrom)] to result in a one-dimensional hydrogen-bonded chain structur e.