Crystal structures of bis(2,2 '-iminodipyridinium) mu-oxalatobis(4-hydroxy-2,6-pyridine-dicarboxylatodibutylstannate) di-2-pyridylamine octahydrate and bis[aquadibutyl(2,6-pyridine-dicarboxylato)tin] di-2-pyridylamine (1/1)

The two independent dianions in bis(2,2'-iminodipyridinium) mu-oxalatobis(4 -hydroxy-2,6-pyridinedicarboxylatodibutylstannate) di-2-pyridylamine octahy drate each consists of two O,N,O-chelated dibutyl(4-hydroxy-2,6-dipyridined icarboxyalto)tin entities that are bridged by a centrosymmetric quadridenta te oxalato group; the tin atoms show trans-C2SnNO5 pentagonal bipyramidal c oordination [C-Sn-C = 173.1(2), 174.3(2)degrees]. The stannate ions, 2,2'-i minodipyridinium cations and the lattice molecules are linked into a three- dimensional network structure by hydrogen bonds. In bis[aquadibutyl(2,6-pyr idinedicarboxylato)tin] di-2-pyridylamine (1/1) co-crystal, the dimeric nat ure of the centrosymmetric bis[aquadibutyl(2,6-pyridinedicarboxylato)tin] e ntity arises from bridging through a carboxyl oxygen atom. The seven-coordi nate tin atom shows pentagonal bipyramidal coordination [C-Sn-C = 161.1 (2) degrees]. The bis[aqua(2,6-pyridinedicarboxylato)tin] portion of the dimer is flat, and adjacent dimers are hydrogen bonded [O-water ... O = 2.675 (4) , 2.780 (4) Angstrom] into flat sheets. Disordered di-2-pyridylamine molecu les occupy the space between the sheets.