Syntheses, structures, and properties of three novel coordination polymersof silver(I) aromatic carboxylates with hexamethylenetetramine exhibiting unique metal-pi interaction

Three interesting coordination polymers, [Ag-4(mu (4)-hmt)(mu (4)-hmt)(mu ( 4)-eta (2)-nda)(2)]. 2H(2)O (1), [Ag-2(mu -hmt)(2)- (mu -bi-eta (2)-bna)]. 2H(2)O . MeCN (2), and [Ag-2(mu (4)-hmt)(eta (2) -hna)(MeCN)](hna).H2O (3) (hmt = hexamethylenetetramine, nda = 2,6-naphthalenedicarboxylate, bna = 2, 2'-dihydroxy-1,1'-binaphthalene-3,3'-dicarboxylate, and hna = 1-hydroxy-2-n aphthalenecarboxylate), were obtained from the reaction of silver(I) aromat ic carboxylates in MeCN solution with hmt in CH2Cl2 solution via the liquid diffusion method. In these complexes, the aromatic carboxylates ligate to the metal atoms via a unique eta (2)-coordination mode involving their arom atic rings, in addition to the normal coordination modes utilizing their ca rboxylate oxygen atoms. These complexes show interesting electronic propert ies similar to those reported for the silver(I) complexes of other polycycl ic aromatic compounds. Both 1 and 2 exhibit a strong blue photoluminescence at room temperature.