Four sodium tetrafluoroborate directed supramolecular networks having 3- and 3,8-disubstituted 1,10-phenanthroline ligands

Four novel sodium tetrafluoroborate directed supramolecular networks having 3- and 3,8-disubstituted 1,10-phenanthroline (phen) ligands, formulated as [Na(3-bromo-phen)2BF4] (1), [Na(3-bromo-phen)BF4]4 (2), [Na(3,8-dibromo-phen)BF4]n (3) and [Na(3-(thiophen-2′-yl)-phen)BF4]n (4), have been prepared and structurally characterized, together with 3,8-dibromo-1,10-phenanthroline (5). Versatile coordination numbers for the sodium(I) centers (varying from 3, 4, 6 to 7) and coordination modes for the phen-based ligands (monodentate and bidentate) have been observed, where different coordinating and bridging fashions for the tetrafluoroborate anions as well as dissimilar intermolecular π–π stacking and hydrogen bonding interactions have been found in mononuclear complex 1, tetranuclear complex 2, one-dimensional (1D) and two-dimensional (2D) coordination polymers 3 and 4. By checking the latest version of CCDC databases, it is found that the structural examples are all very rare on the monodentate coordination mode for the phen-based ligand, the presence of three and four-coordinate sodium(I) coordination centers and the sodium(I)–thiophene coordination bonds.