[Nb 6 Cl 14 (pyrazine) 4 ], a Versatile Precursor for Ligand-Supported Hexanuclear Niobium Cluster Compounds: Synthesis, Characterization, Follow-Up Reactions, and Intermolecular Interactions.

The compound [Nb 6 Cl 14 (pyrazine) 4 ]·2CH 2 Cl 2 ( 1 ) was investigated for its suitability as a starting compound for new ligand-supported hexanuclear niobium cluster compounds. The synthesis, stability to air and increased temperature, solubility and usability for subsequent reactions of 1 , and purification and separation of the reaction products are discussed. The compounds with cluster units [Nb 6 Cl 14 L 4 ], where L = iso-quinoline N -oxides ( 2 ), 1,1-dimethylethylenediamines ( 3 ), or thiazoles ( 4 ), and [Nb 6 Cl 14 (PEt 3 ) 3.76 (Et 3 PO) 0.24 ][Nb 6 Cl 14 (MeCN) 4 ]·4MeCN ( 5 ) are presented as follow-up products. The crystal structures of compounds 1-5 are analyzed, and the structures are discussed with respect to their intra- and intermolecular bonding situations and crystal packing. In addition to hydrogen bonds and π-π interactions, the appearance of chalcogen and halogen bonds and lone pair-π interactions between Nb 6 cluster units was observed for the first time.