Synthesis and characterization of compounds containing discrete tetranuclear clusters and extended arrays of molybdenum atoms

Thesis/Dissertation · Tue Jan 01 04:00:00 EST 1985

OSTI ID:5502090

Aufdembrink, B A

Improved synthetic pathways to the Mo/sub 4/Cl/sub 8/L/sub 4/ cluster compounds were elucidated which provide a facile entrance to the synthesis of new four metal atom clusters. The new tetranuclear clusters, with the stoichiometry R/sub 4/Mo/sub 4/Cl/sub 12/ (R = Et/sub 4/N, Pr/sub 4/N, O/sub 4/P), were prepared by the reaction of tealkylammonium or tetraphenylphosphonium chlorides with the rectangular tetrameric cluster Mo/sub 4/Cl/sub 8/L/sub 4/. One electron oxidation of Mo/sub 4/Cl/sub 12//sup 4 -/ by I/sub 2/ or dichlorophenyliodine yielded the Mo/sub 4/Cl/sub 12//sup 3 -/ cluster anion, which was shown to exist as two geometric isomers, both of which are fragments of the larger hexanuclear cluster anion Mo/sub 6/Cl/sub 14//sup 2 -/. The metal atoms in (Et/sub 4/N)/sub 3/Mo/sub 4/Cl/sub 12/ form an opened tetrahedron or butterfly. In (O/sub 4/P)/sub 3/Mo/sub 4/Cl/sub 12/, (Pr/sub 4/N)/sub 3/-Mo/sub 4/Cl/sub 12/, and (O/sub 4/As)/sub 2/(Et/sub 4/N)Mo/sub 4/Cl/sub 12/ the metal atoms form a planar rhomboidal cluster unit. Bond distances in both cluster units are indicative of strong metal-metal bonding. Magnetic susceptibility and electron paramagnetic resonance studies of (O/sub 4/P)/sub 3/Mo/sub 4/Cl/sub 12/ are consistent with the assignment of one unpaired electron, delocalized over the cluster unit. The ternary molybdenum oxide, Sn/sub 0.9/Mo/sub 4/O/sub 6/, was synthesized by high temperature reactions in sealed molybdenum tubes. The structure of this compound is dominated by metal-metal bonded octahedral clusters which are fused on trans edges to form infinite chains through the lattice. Four such clusters are interconnected to form a tetragonal tunnel occupied by Sn. Resistivity studies show the compound is metallic. The compound exhibits weak, temperature independent paramagnetism.

• Research Organization: Iowa State Univ. of Science and Technology, Ames (USA)
• DOE Contract Number: W-7405-ENG-82
• OSTI ID: 5502090
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201* -- Chemical & Physicochemical Properties
400301 -- Organic Chemistry-- Chemical & Physicochemical Properties-- (-1987)
ARSENIC COMPOUNDS
ARSENIC OXIDES
CHALCOGENIDES
CHEMICAL BONDS
MOLYBDENUM COMPOUNDS
NITRIDES
NITROGEN COMPOUNDS
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
PHOSPHORUS COMPOUNDS
PHOSPHORUS OXIDES
PNICTIDES
PRASEODYMIUM COMPOUNDS
PRASEODYMIUM NITRIDES
RARE EARTH COMPOUNDS
REFRACTORY METAL COMPOUNDS
SYNTHESIS
TIN COMPOUNDS
TIN OXIDES
TRANSITION ELEMENT COMPOUNDS