Syntheses, Structures, and Luminescence Properties of New Octahedral Cluster Complexes with Terminal Phenolate Ligands: [K(H2O)(CH3OH)3]2[Ph4P]2[M 6Cl12(O–C6H4–F)6] (M = Nb, Ta; Ph = phenyl)

Abstract

The cluster compounds [K(H 2 O)(CH 3 OH) 3 ] 2 [Ph 4 P] 2 [M 6 Cl 12 (para-O-C 6 H 4 -F) 6 ] (M = Nb (1), Ta (2); Ph=phenyl) were obtained by the reaction of [Nb 6 Cl 14 (CH 3 OH) 4 ]Á6 CH 3 OH with potassium p-fluorophenolat and tetraphenylphosphonium chloride. 1 and 2 were crystallized from CH 3 OH and characterized by X-ray single-crystal diffraction, IR-, 1 H NMR-,UV-Vis-and luminescence spectroscopy.

Hexanuclear Niobium Cluster Alcoholates – First Representatives with Isopropanolato Ligands

“…At temperatures below ∼60 °C the substitution of the outer ligands preferably happens. This holds for the cluster unit in 1 as well as for example for the structurally characterized Nb 6 cluster ions [Nb 6 Cl i 12 (OCH 3 ) a 6 ] 4− , [Nb 6 Cl i 12 (OC 6 H 4 F) a 6 ] 4− , or the neutral cluster unit [Nb 6 Cl 12 (CH 3 OH) 4 (OCH 3 ) 2 ] [28–30] . However, using reaction temperatures between 60 °C and 120 °C the preparation of Nb 6 or Ta 6 cluster compounds carrying alcoholato ligands on the inner sites is achieved, see compounds 2 , 3 , and 4 , or e. g. [K(CH 3 OH) 4 ] 2 [Nb 6 (OCH 3 ) 18 ] [25] .…”

“…This holds for the cluster unit in 1 as well as for example for the structurally characterized Nb ]. [28][29][30] However, using reaction temperatures between 60 °C and 120 °C the preparation of Nb 6 or Ta 6 cluster compounds carrying alcoholato ligands on the inner sites is achieved, see compounds 2, 3, and 4, or e. g. [K(CH 3 OH) 4 ] 2 -[Nb 6 (OCH 3 ) 18 ]. [25] In this context, the cluster unit in…”

[Nb6Cl14(pyrazine)4], a Versatile Precursor for Ligand-Supported Hexanuclear Niobium Cluster Compounds: Synthesis, Characterization, Follow-Up Reactions, and Intermolecular Interactions

“…For cluster compounds with the [Nb 6 Cl 12 ] n + unit ( n = 2, 3, or 4), the mostly used precursor compounds are limited to A 4 [Nb 6 Cl 18 ] (A = alkaline metal cation), − [Nb 6 Cl 14 (H 2 O) 4 ]·4H 2 O (generated from K 4 [Nb 6 Cl 18 ]), and [Nb 6 Cl 14 (CH 3 OH) 4 ]·6CH 3 OH . K 4 [Nb 6 Cl 18 ] was first published by von Schnering, Simon, and Schäfer and used extensively − but has disadvantages in that it is not very soluble and reaction mixtures always carry large amounts of KCl, which often interferes the crystallization of pure reaction products. The use of the “salt-free” amorphous [Nb 6 Cl 14 ] has not attracted much attention .…”