The structures of two scorpionates: thallium tetrakis(3-phenyl-1H-pyrazol-1-yl)borate and potassium tetrakis(3-cyclopropyl-1H-pyrazol-1-yl)borate
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)], and catena-poly[potassium-[2-tetrakis(3-cyclopropyl-1H-pyrazol-1-yl)borato]], [K(C24H28BN8)]n, have been determined at 296 K in the monoclinic P21/c and C2/c space groups, respectively. In their crystal structures, the thallium salt presents discrete molecular motifs, while the potassium salt shows infinite polymeric chains. The 13C and 15N 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.