title: Neutron diffraction studies of a four-coordinated hydride in near square-planar geometry.
abstract: The structure of a nanospheric polyhydrido copper cluster, [Cu20(H)11{S2P(O(i)Pr)2}9], was determined by single-crystal neutron diffraction. The Cu20 cluster consists of an elongated triangular orthobicupola constructed from 18 Cu atoms that encapsulate a [Cu2H5](3-) ion with an exceptionally short Cu-Cu distance. The 11 hydrides in the cluster display three different coordination modes to the Cu atoms: six μ3-hydrides in a pyramidal geometry, two μ4-hydrides in a tetrahedral cavity, and three μ4-hydrides in an unprecedented near square-planar geometry. The neutron data set was collected for 7 days on a small crystal with dimensions of 0.20 mm × 0.50 mm × 0.65 mm using the Spallation Neutron Source TOPAZ single-crystal time-of-flight Laue diffractometer at Oak Ridge National Laboratory. The final R-factor was 8.63% for 16,014 reflections.
authors.affiliation: Department of Chemistry, National Dong Hwa University , Hualien 97401, Taiwan, R.O.C.
authors.forename: Jian-Hong
authors.initials: JH
authors.lastname: Liao
authors.forename: Rajendra Singh
authors.initials: RS
authors.lastname: Dhayal
authors.forename: Xiaoping
authors.initials: X
authors.lastname: Wang
authors.forename: Samia
authors.initials: S
authors.lastname: Kahlal
authors.forename: Jean-Yves
authors.initials: JY
authors.lastname: Saillard
authors.forename: C W
authors.initials: CW
authors.lastname: Liu