Syntheses and structures of some adducts of silver(I) oxyanion salts with some 2-N,O-donor-substituted pyridine bases

Syntheses and room-temperature single crystal X-ray structural characterizations are recorded for a variety of silver(I) oxyanion (perchlorate, nitrate and trifluoroacetate (‘tfa’) (increasing basicity)) adducts, AgX, with a number of pyridine (‘py’) bases, L, functionalized in the 2-position with N- or O-donor groups, namely 2-amino-, 2-amino-6-methyl-, 2-aminomethyl-, 2-hydroxy-, 2-methoxy- and 2-acetyl- pyridines, ‘2np’, ‘nmp’, ‘amp’, ‘ohp’, ‘mop’, and ‘acp’. A variety of stoichiometries and associated structural types are defined: [Ag(chelate)2]X, L/X = amp,acp/ClO4, [XAg(chelate)2], L/X = acp/tfa, of 1:2 AgX:L stoichiometry; for 1:1 stoichiometry, although a discrete mononuclear complex [(chelate)Ag(O2NO)] is defined for AgNO3: acp (1:1), all others are polymers, successive silver atoms being linked by N,N′-bridging ligands singly (L/X = 2np/ClO4 (⋯HAgHTAgTHAgH⋯), amp/ClO4, NO3 (⋯HTAgHTAg⋯) (‘H’ ≡ head, ‘T’ = tail)) or pairwise, ⋯L2AgX2AgL2Ag⋯ (L/X = 2np/tfa, nmp/NO3). More complex polymeric arrays are found with L/X = ohp/NO3, tfa, where interaction with the metal takes place via the O-donor only, the py functionality being protonated, and in adducts of more complex stoichiometry AgNO3:mop (2:3) and AgNO3:2np (3:4).

Adducts of silver(I) salts of oxyanions of increasing base strength with pyridine bases functionalized in the 2-position by N- or O-donor groups show a variety of structures in which the functionalized pyridine may behave as a bidentate chelating ligand or a bridging ligand. In the case of 2-hydroxypyridine, coordination involves the O-donor only, with the proton being transferred to the pyridine N atom.Figure optionsDownload as PowerPoint slide