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

Lourdes Infantes; Rosa M Claramunt; Dionisia Sanz; Ibon Alkorta; José Elguero

doi:10.1107/S2053229616007385

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

Acta Crystallogr C Struct Chem. 2016 Nov 1;72(Pt 11):819-825. doi: 10.1107/S2053229616007385. Epub 2016 Oct 5.

Authors

Lourdes Infantes¹, Rosa M Claramunt², Dionisia Sanz², Ibon Alkorta³, José Elguero³

Affiliations

¹ Departamento de Cristalografía y Biología Estructural, Instituto de Química-Física Rocasolano, CSIC, Serrano 119, Madrid 28006, Spain.
² Departamento de Química Orgánica y Bio-Orgánica, Facultad de Ciencias, UNED, Paseo Senda del Rey 9, Madrid 28040, Spain.
³ Instituto de Química Médica, CSIC, Juan de la Cierva 3, Madrid 28006, Spain.

PMID: 27811418
DOI: 10.1107/S2053229616007385

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)], and catena-poly[potassium-[μ₂-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.

Keywords: complementary techniques; conformation; coordination chemistry; crystal structure; scorpionate; solid-state NMR; tetrakis(1H-pyrazol-1-yl)borate.