Keum Yoon

Tris(3-t-butyl-5-methylpyrazolyl)hydroborato derivatives of copper and thallium: The structural influence of a 5-methyl substituent

The molecular structures of the tris(3-t-butyl-5-methylpyrazolyl)hydroborato derivatives of copper and thallium {[TpBut,Me]Cu}2, [TpButMe]CuCl and Tl[TpBut,Me], have been determined by X-ray diffraction. Comparison of these structures with those of {[TpBut]Cu}2, [TpBut]CuCl and Tl[TpBut] demonstrates the structural role that alkyl substitution at the remote 5-position of the pyrazolyl group may play in modifying the coordination environment about a metal centre.

The synthesis of [HB]3,5-(Butph)2pz]3]− (Butph = p-C6H4But), a new tris(pyrazolyl)hydroborato ligand: the crystal and molecular structure of Tl{η3-HB[3,5-(Butph)2pz]3}

Abstract The synthesis of a new sterically demanding tris(pyrazolyl)hydroborato ligand, [HB[3,5-(Butph)2pz]3]− (Butph = para-C6H4But), is reported. The potassium derivative is prepared by the direct reaction of KBH4 with 3,5-bis(para-tert-butylphenyl)pyrazole. Metathesis with TlNO3 converts the potassium derivative to the thallium complex Tl{η3-HB[3,5-(Butph)2pz]3}. The crystal and molecular structures of the pyrazole derivative [3,5-(Butph)2pz]2ZnI2 and the thallium derivative Tl{η3-HB[3,5-(Butph)2pz]3} have been determined.

Origin of the two significantly different W–Cl bond lengths for chemically equivalent bonds in mer-[WCl3(PMe2Ph)3]

The observation of two significantly different W–Cl bond lengths for chemically equivalent bonds, previously reported for mer-[WCl3(PMe2Ph)3], has been reinterpreted as an artifact due to cocrystallization with an isostructural oxo impurity, cis-mer-[WOCl2(PMe2Ph)3].