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Stabilization of Decatellurium Molecules in Isolated and Concatenated Clusters
Author(s) -
Günther Anja,
Isaeva Anna,
Ruck Michael
Publication year - 2013
Publication title -
zeitschrift für anorganische und allgemeine chemie
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.354
H-Index - 66
eISSN - 1521-3749
pISSN - 0044-2313
DOI - 10.1002/zaac.201200430
Subject(s) - tellurium , crystallography , triclinic crystal system , chemistry , octahedron , molecule , transition metal , trigonal prismatic molecular geometry , chalcogen , main group element , crystal structure , stereochemistry , inorganic chemistry , biochemistry , organic chemistry , catalysis
Black, shiny crystals of the molecular cluster compounds (Te 10 )[ M (Te X 4 )(Te X 3 )] 2 ( M / X = Rh/Cl ( 1 ), Ir/Br ( 2 )), (Te 10 )[Ru(TeI 4 )(TeI 2 )] 2 ( 3 ), (Te 10 )[ M (TeI 4 )(TeI 2 )] 2 (TeI 4 )(Te 2 I 2 ) ( M = Rh ( 4 ), Ir ( 5 )) as well as the one‐dimensional cluster polymer (Te 10 I 2 )[Ir(TeI 4 )] 2 (Te 4 )I 2 ( 6 ) were synthesized by melting reactions of an electron‐rich transition metal M ( M = Ru, Rh, Ir) with tellurium and Te X 4 ( X = Cl, Br, I). X‐ray diffraction on single‐crystals revealed that the compounds crystallize in the triclinic space group type P $\bar{1}$ . 4 and 5 show [3+1]‐dimensional modulations of their structures. All compounds contain binuclear complexes with central μ‐η 4 :η 4 ‐bridging Te 10 units and terminal halogenidotellurate(II) groups. Each of the transition metal cations is in a slightly distorted octahedral coordination by six tellurium atoms; the two [ M Te 6 ] octahedra share a common edge. With the tellurium atoms acting as electron‐pair donors, the 18 electron rule is fulfilled for the electrophilic M atoms. The central tricyclo [5.1.1.1 3, 5 ]‐decatellurium molecule consists of two ecliptically stacked Te 4 rings, which are linked through two tellurium atoms. The symmetric or asymmetric 3c4e bonds along these almost linear bridges are in analogy to polyanionic forms of tellurium, while the tricyclic conformation is stabilized by the strong bonding to the transition‐metal cations. Multi‐center bonding (3c4e) is also present in the terminal square [Te +II X 4 ] 2– and the T‐shaped [Te +II X 3 ] – groups. The crystal structures of 4 and 5 are organized in layers of (Te 10 )[ M (TeI 4 )(TeI 2 )] 2 n+ clusters ( n ≤ 2) that are quite robust upon oxidation or reduction as shown by molecular calculations. These clusters alternate with incommensurately modulated layers that probably consist of TeI 4 2– anions and a previously unknown Te 2 I 2 molecule. The uncertainty arises primarily from equal scattering powers of I and Te atoms as well as from the known flexibility of the electron count of the Te 10 unit. In 6 , neutral Te 4 rings concatenate (Te 10 I 2 )[Ir(TeI 4 )] 2 clusters into chains, which run parallel to the a axis.