CATION-ANION INTERACTIONS INVOLVING HYDROGEN-BONDS - SYNTHESES, STRUCTURES AND SPECTROSCOPIC STUDIES OF [H-2DAM][BI(III)PH(O2CCF3)(4)], [HPY](2)[BI(III)PH(O2CCF3)(4)] AND [H-2DAM][BI(III)(O2CCF3)(5)] (DAM = DIAMINE, PY = PYRIDINE)

New anionic bismuth(III) complexes [H-2dam][BiPh(O2CCF3)4] 1, [Hpy]2[B iPh(O2CCF3)4] 1g and [H-2dam] [Bi(O2CCF3)2] 2 (dam = diamine, py = pyr idine) have been synthesised by the reaction of BiPh, with trifluoroac etic acid and diamines or pyridine. The crystal structures of [H-2dam] [BiPh(O2CCF3)4] [dam = Me2N (CH2)3NMe2 1 a, Me2NCH2CH(OH)CH2NMe2 1 b, Me2N (CH2)4NMe2 1 C, Me2N(CH2)2NMe2 ld or N,NN',N'-tetramethyl-1,4-ph enylenediamine 1f], 1g, and [H-2teed][Bi(O2CCF3)5] 2e [teed = Et2N(CH2 )2NEt2] have been determined by single-crystal X-ray diffraction analy ses. The structure of the [BiPh(O2CCF3)4]2- anion in the solid state h as been found to be dependent on the structure of the protonated diami ne or pyridine. In la-lc it has a cup-like structure with the Bi(III) adopting a square-pyramidal geometry, while in ld it has an irregular shape with the Bi(III) of approximate pentagonal-pyramidal geometry. T he [BiPh(O2CCF3)4]2- anion in 1f and 1g has intermediate structure bet ween the 'cup' and the pentagonal pyramid. Compound 2e has an irregula r polyhedral geometry and the bismuth is surrounded by ten oxygen atom s. The structural variations observed in these compounds are attribute d to hydrogen-bonding interactions between the anion and the cation, a nd the stacking of aromatic rings in the crystal lattice. The solution behaviour of [BiPh(O2CCF3)4]2- has been examined by H-1 NMR spectrosc opic analysis. In cases where the dam is an aliphatic diamine, compoun d 1 is in equilibrium with [H-2dam][Bi(O2CCF3)5] 2 and [Hdam][BiPh2(O2 CCF3)2] 3, except for lb which undergoes irreversible decomposition in solution. When dam is an aromatic diamine or pyridine the [BiPh(O2CCF 3)4]2-anion is stable in solution. Solvent molecules such as tetrahydr ofuran or acetone have been found to affect the equilibrium between co mpounds 1 and 2 and 3.