The structures of two scorpionates: thallium tetrakis(3-phenyl-1H-pyrazol-1-yl)borate and potassium tetrakis(3-cyclopropyl-1H-pyrazol-1-yl)borate

Abstract

The introduction of poly(1H-pyrazolyl)borate anions, better known as scorpionates, as negatively charged ligands for a great diversity of metal cations has had a tremendous influence in coordination chemistry. The structures of two salts of tetrakispyrazolylborate, namely [tetrakis(3-phenyl-1H-pyrazol-1-yl)borato]thallium(I), [Tl(C36H28BN8)], andcatena-poly[potassium-[μ2-tetrakis(3-cyclopropyl-1H-pyrazol-1-yl)borato]], [K(C24H28BN8)]n, have been determined at 296 K in the monoclinicP21/candC2/cspace groups, respectively. In their crystal structures, the thallium salt presents discrete molecular motifs, while the potassium salt shows infinite polymeric chains. The13C and15N CPMAS (cross polarization magic angle spinning) NMR spectra of these compounds were recorded and the chemical shifts compared with theoretically calculated ones at the GIAO/B3LYP/6-311++G(d,p) level. Both techniques are complementary and mutually consistent.