@article{SperlichKoeckerling2023,
  author    = {Sperlich, Eric and K{\"o}ckerling, Martin},
  title     = {The double cluster compound [Nb6Cl14(MeCN)(4)] [Nb6Cl14(pyz)(4)].6MeCN (Me: methyl, pyz: pyrazine) with a layered structure resulting from weak intermolecular interactions},
  series = {Zeitschrift f{\"u}r Naturforschung},
  volume    = {78},
  journal   = {Zeitschrift f{\"u}r Naturforschung},
  number    = {5},
  publisher = {De Gruyter},
  address   = {Berlin},
  issn      = {0932-0776},
  doi       = {10.1515/znb-2023-0001},
  pages     = {279 -- 283},
  year      = {2023},
  abstract  = {The synthesis and the crystal structure of the double cluster compound [Nb6Cl14(MeCN)(4)][Nb6Cl14(pyz)(4)]middot6CH(3)CN are described. The synthesis is based on a partial ligand exchange reaction, which proceeds upon dissolving [Nb6Cl14(pyz)(4)]middot2CH(2)Cl(2) in acetonitrile. The compound is built up of two discrete neutral cluster units, which consist of octahedra of Nb-6 atoms coordinated by 12 edge-bridging chlorido and two terminal chlorido ligands, and four acetonitrile ligands on one and four pyrazine ligands on the other cluster unit. Co-crystallized acetonitrile molecules are also present. The single-crystal structure determination has revealed a cluster arrangement in which the [Nb6Cl14(pyz)(4)] units are connected by (halogen) lone-pair-(pyrazine) pi interactions. These lead to chains of [Nb6Cl14(pyz)(4)] clusters. These chains are further connected to cluster layers by (nitrile-halogen) dipole-dipole interactions, in which the [Nb6Cl14(MeCN)(4)] and co-crystallized MeCN molecules are also involved. These cluster layers are arranged parallel to the crystallographic {011} plane.},
  language  = {en}
}
@article{SperlichKoeckerling2021,
  author    = {Sperlich, Eric and K{\"o}ckerling, Martin},
  title     = {Cluster salts [Nb6Cl12(HIm)(6)]A(n) (with HIm=1H-imidazole and A=Mineral Acid Anion, n=1 or 2) made in and with Bronsted-basic ionic liquids and liquid mixtures},
  series = {ChemistryOpen},
  volume    = {10},
  journal   = {ChemistryOpen},
  number    = {2},
  publisher = {Wiley-VCH},
  address   = {Weinheim},
  issn      = {2191-1363},
  doi       = {10.1002/open.202000266},
  pages     = {248 -- 254},
  year      = {2021},
  abstract  = {Four new hexanuclear niobium cluster compounds of the general formula [Nb6Cl12(HIm)(6)](A)(n) . x(solvent molecule) (HIm=1H-imidazole, A=mineral acid anion, Cl- (n=2) (1), (SO4)(2-) (n=1) (2), (CrO4)(2-) (n=1) (3), and (HAsO4)(2-) (n=1) (4)) were prepared. Their synthesis can be done in basic ionic liquids, which form on the addition of a mineral acid, which also delivers the counter anion for the final cluster compound, to an excess of the 1H-imidazole. Some addition of an auxiliary solvent, like methanol, improves the speed of crystallisation. The cluster unit comprises a hexanuclear Nb-6 unit of octahedral shape with the edges bridged by Cl atoms and the exo sites being occupied by N-bonded 1H-imidazole ligands. The cluster cation carries sixteen cluster-based electrons. Between the NH groups of the ligands of the cluster unit, the anions and the co-crystallised water (1), or 1H-imidazole and methanol molecules (2, 3, and 4) a network of hydrogen bonds exists.},
  language  = {en}
}