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

Eric Sperlich; Martin Köckerling

doi:10.1021/acs.inorgchem.1c03109

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

Inorg Chem. 2022 Feb 7;61(5):2409-2420. doi: 10.1021/acs.inorgchem.1c03109. Epub 2022 Jan 24.

Authors

Eric Sperlich¹, Martin Köckerling^{2

3}

Affiliations

¹ University of Potsdam Institute of Chemistry, Karl-Liebknecht-Strasse 24-25, D-14476 Potsdam, Germany.
² University of Rostock, Institute of Chemistry, Solid-State Inorganic Chemistry Group, Albert-Einstein-Strasse 3a, D-18059 Rostock, Germany.
³ University of Rostock, Department Life, Light and Matter, D-18051 Rostock, Germany.

PMID: 35072457
DOI: 10.1021/acs.inorgchem.1c03109

Abstract

The compound [Nb₆Cl₁₄(pyrazine)₄]·2CH₂Cl₂ (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 [Nb₆Cl₁₄L₄], where L = iso-quinoline N-oxides (2), 1,1-dimethylethylenediamines (3), or thiazoles (4), and [Nb₆Cl₁₄(PEt₃)_3.76(Et₃PO)_0.24][Nb₆Cl₁₄(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 Nb₆ cluster units was observed for the first time.