Metal-metal-bonded compounds of lower-valent niobium and tantalum. Compounds containing the [Nb[sub 2]Cl[sub 7](PR[sub 3])[sub 2]][sup [minus]] and [Nb[sub 3]Cl[sub 10](PR[sub 3])[sub 3]][sup [minus]] ions and some clues as to how higher-nuclearity clusters are formed

Journal Article · Wed Mar 17 04:00:00 EST 1993 · Inorganic Chemistry; (United States)

DOI:https://doi.org/10.1021/ic00058a037· OSTI ID:6623931

Cotton, F A; Shang, Maoyu ^[1]

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1. Texas A M Univ., College Station (United States)

Two examples of a new type of face-sharing bioctahedral diniobium cluster that contain three bridging chloride ligands and two terminal phosphines in a syn configuration, (Bu[sub 4]N)[Nb[sub 2]Cl[sub 7](PEt[sub 3])[sub 2]] (1) and (Bu[sub 4]N)[Nb[sub 3]Cl[sub 10](PMe[sub 3])[sub 3]](BF[sub 4])[center dot]THF (2), as well as a related triangular trinuclear niobium cluster, (HPMe[sub 3])(Bu[sub 4]N)[Nb[sub 3]Cl[sub 10](PMe[sub 3])[sub 3]](BF[sub 4])[center dot]THF (3), have been synthesized and characterized by X-ray diffraction. Complex 1 crystallizes in the space group R[bar 3]c, with a = b = 32.265(3) [Angstrom], c = 25.579(3) [Angstrom], V = 23061(8) [Angstrom][sup 3], and Z = 18; Nb-Nb distance = 2.708(3) [Angstrom]. Compound 2 belongs to the space group P2[sub 1], with a = 10.177(4) [Angstrom], b = 19.602(3) [Angstrom], c = 10.557(3) [Angstrom], [beta] = 90.38(3)[degrees], V = 2105(1) [Angstrom][sup 3], and Z = 2; Nb-Nb distance = 2.683(1) [Angstrom]. The trinuclear cluster 3 crystallizes in the space group R[bar 3], with a = b = 40.595(5) [Angstrom], c = 19.253(4) [Angstrom], V = 27477(8) [Angstrom][sup 3], and Z = 18; average Nb-Nb distance = 2.959[12] [Angstrom] (2.974(3), 2.944(3), and 2.958(3) [Angstrom]). Compounds 1 and 2 have effective magnetic moments 0.84 and 0.99 [mu][sub B] at room temperature, respectively. A conversion from [Nb[sub 2]Cl[sub 7](PEt[sub 3])[sub 2]][sup [minus]] to [Nb[sub 3]Cl[sub 10](PEt[sub 3])[sub 3]][sup [minus]] has been observed and is discussed. Pathways of conversion from edge-sharing bioctahedral Nb[sub 2]Cl[sub 6](PEt[sub 3])[sub 4] to the face-sharing [Nb[sub 2]Cl[sub 7](PEt[sub 3])[sub 2]][sup [minus]] and finally to triangular trinuclear [Nb[sub 3]Cl[sub 10](PEt[sub 3])[sub 3]][sup [minus]] or even larger clusters are discussed. 35 refs., 5 figs., 11 tabs.

• OSTI ID: 6623931
• Journal Information: Inorganic Chemistry; (United States), Journal Name: Inorganic Chemistry; (United States) Vol. 32:6; ISSN 0020-1669; ISSN INOCAJ
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201* -- Chemical & Physicochemical Properties
ABSORPTION SPECTROSCOPY
ANIONS
CHARGED PARTICLES
CHLORIDES
CHLORINE COMPOUNDS
COHERENT SCATTERING
CRYSTAL STRUCTURE
DIFFRACTION
HALIDES
HALOGEN COMPOUNDS
IONS
LATTICE PARAMETERS
LIGANDS
MAGNETIC MOMENTS
MOLECULAR STRUCTURE
NIOBIUM COMPOUNDS
PHOSPHINES
PHOSPHORUS COMPOUNDS
REFRACTORY METAL COMPOUNDS
SCATTERING
SPECTROSCOPY
TRANSITION ELEMENT COMPOUNDS
X-RAY DIFFRACTION