An Unprecedented Cluster Unit in (BMIm)2[Hf9Cl14H8(AlCl4)6]. Issue 46 (23rd November 2021)

• Record Type: Journal Article
• Authors: Jablonski, Jonas; Bresien, Jonas; Köckerling, Martin
• Is Part Of: European journal of inorganic chemistry. Issue 46(2021)
• Page Start: 4776
• Page End: 4780
• Publication Date: 2021-11-23
• Subjects: Cluster compounds -- Density functional calculations -- Electronic structure -- Hafnium -- Metalloid clusters -- Structure elucidation; Chemistry, Inorganic -- Periodicals; Organometallic chemistry -- Periodicals; Bioinorganic chemistry -- Periodicals; Solid state chemistry -- Periodicals; 546
• DOI: 10.1002/ejic.202100191
• Languages: English
• ISSNs: 1434-1948

Abstract

Abstract: The reduction of HfCl4 with Li[AlH4 ] under ionothermal conditions using (BMIm)[AlCl4 ] as solvent and as reactant gives the compound (BMIm)2 [Hf9 Cl14 H8 (AlCl4 )6 ] in moderate yield. It contains nona‐nuclear metalloid cluster units with an unprecedented arrangement of the metal atoms. This can be described by a polyhedron consisting of two trigonal bipyramids, which are fused in one basal Hf atom. The edges of the Hf9 polyhedron are bridged by Cl atoms and the apical sites Cl‐bonded to [AlCl4 ] − anions. These bridge the cluster units into 1D cluster strands. The metal atom polyhedron can be constructed by a step‐wise distortion of a body centred cube. DFT calculations on [Hf9 Cl14 H(8‐x) (AlCl4 )6 ] 2− units for different numbers of hydrogen atoms (x=8–0) at the UPBE‐D3/def2‐TZVP level of theory indicate significant metal‐metal bonding. These calculations supported strongly the presence of hydridic H atoms bridging triangular faces of the metal atom skeleton. The most stable cluster anion is calculated for eight H atoms present in the cluster unit. Abstract : The reduction of HfCl4 with Li[AlH4 ] under ionothermal conditions affords the cluster compound (BMIm)2 [Hf9 Cl14 H8) (AlCl4 )6 ], which has a previously unknown arrangement of metal atoms. Two trigonal bipyramids of Hf atoms are fused at one atom. DFT calculations show a significant stabilization for the anion with 8 H atoms bridging trigonal faces of the metal atom arrangement.