ISSN:
0044-2313
Keywords:
Octa-μ3-chloro-hexaisocyanato-octahedro-hexamolybdate(2-)
;
Octa-μ3-bromo-hexaisocyanato-octahedro-hexamolybdate(2-)
;
Octa-μ3-chloro-hexaisoselenocyanato-octahedro-hexamolybdate(2-)
;
Octa-μ3-bromo-hexaisoselenocyanato-octahedro-hexamolybdate(2-)
;
Synthesis, Crystal Structure
;
Vibrational Spectra
;
Normal Coordinate Analysis
;
Force Constants
;
Chemistry
;
Inorganic Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Description / Table of Contents:
Synthesis, Crystal Structures, Vibrational Spectra, and Normal Coordinate Analysis of (TBA)2[(Mo6X8i)Y6a]; Xi = Cl, Br; Ya = NCO, NCSeBy treatment of [(Mo6X8i)I6a]2-, Xi = Cl, Br with AgNCO in acetone the hexaisocyanato derivates [(Mo6Cl8i)(NCO)6a]2- and [(Mo6Br8i)(NCO)6a]2- are formed, whereas the reaction with AgNO3 and KNCSe yields [(Mo6Cl8i)(NCSe)6a]2- and [(Mo6Br8i)(NCSe)6a]2-. The X-ray structure determinations on single crystals of (TBA)2[(Mo6Cl8i) (NCO)6a] (1) (triclinic, space group P1, a = 12.006(5), b = 12.084(5), c = 12.143(5) Å, α = 61.974(5)°, β = 75.975(5)°, γ = 76.527(5)°, Z = 1), (TBA)2[(Mo6Br8i) (NCO)6a] (2) (triclinic, space group P1, a = 11.880(5), b = 11.972(5), c = 12.107(5) Å, α = 78.021(5)°, β = 78.320(5)°, γ = 62.660(5)°, Z = 1), (TBA)2[(Mo6Cl8i) (NCSe)6a] · 2 Et2O (3) (monoclinic, space group P21/n, a = 11.30(2), b = 16.472(4), c = 20.134(3) Å, β = 95.43(3)°, Z = 2) and (TBA)2[(Mo6Br8i) (NCSe)6a] · 2 Me2CO (4) (triclinic, space group P1, a = 11.014(2), b = 12.72(2), c = 13.323(1) Å, α = 78.48(2)°, β = 81.92(1)°, γ = 83.11(4)°, Z = 1) reveal that the cyanate and selenocyanate groups are coordinated via the N atoms. The (MoNC) angles are 160.3° (1), 168.1° and 153.8-155.5° (2), 166.1° and 172.6° (3), 172.9° and 147.1-165.1° (4), indicating apical and equatorial groups of ligands in (2), (3), (4). Using the molecular parameters of the X-ray determinations the low temperature (10 K) IR and Raman spectra of the (TBA) cluster salts are assigned by normal coordinate analyses based on a modified valence force field. The (MoN) valence force constants are 2.44 (1), 2.45 (2), 2.02 (3), 1.92 mdyne/ Å (4).
Notes:
Bei der Umsetzung von [(Mo6X8i)I6a]2-; Xi = Cl, Br, mit AgNCO in Aceton entstehen die Hexaisocyanato-Derivate [(Mo6Cl8i)(NCO)6a]2- und [(Mo6Br8i)(NCO)6a]2-, mit AgNO3 und anschließender Zugabe von KNCSe die Hexaisoselenocyanate [(Mo6Cl8i)(NCSe)6a]2- und [(Mo6Br8i)(NCSe)6a]2-. Die Röntgenstrukturanalysen an Einkristallen von (TBA)2[(Mo6Cl8i)(NCO)6a](1) (triklin, Raumgruppe P1, a = 12,006(5), b = 12,084(5), c = 12,143(5) Å, α = 61,974(5)°, β = 75,975(5)°, γ = 76,527(5)°, Z = 1), (TBA)2[(Mo6Br8i)(NCO)6a](2) (triklin, Raumgruppe P1, a = 11,880(5), b = 11,972(5), c = 12,107(5) Å, α = 78,021(5)°, β = 78,320(5)°, γ = 62,660(5)°, Z = 1). (TBA)2[(Mo6Cl8i)(NCSe)6a] · 2Et2O (3) (monoklin, Raumgruppe P21/n, a = 11,30(2), b = 16,472(4), c = 20,134(3) Å, β = 95,43(3)°, Z = 2) und (TBA)2[(Mo6Br8i)(NCSe)6a] · 2Me2CO (4) (triklin, Raumgruppe P1, a = 11,014(2), b = 12,72(2), c = 13,323(1) Å, α = 78,48(2)°, β = 81,92(1)°, γ = 83,11(4)°, Z = 1) zeigen, daß über N gebundene Cyanat- und Selenocyanat-Gruppen vorliegen. Die (MoNC)-Bindungswinkel betragen 160,3° (1), 153,8-155,5° und 168,1° (2), 166,1° und 172,6° (3) sowie 172,9° und 147,1-165,1° (4), was für (2), (3) und (4) auf die Ausbildung apikaler und äquatorialer Ligandengruppen hinweist. Unter Verwendung der röntgenographisch ermittelten Molekülparameter werden die bei 10 K registrierten IR- und Raman-Spektren der (TBA)-Clustersalze durch Normalkoordinatenanalysen auf der Basis eines modifizierten Valenzkraftfeldes zugeordnet. Die (MoN)-Valenzkraftkonstanten betragen 2,44 (1), 2,45 (2), 2,02 (3) und 1,92 mdyn/ Å (4).
Additional Material:
2 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/zaac.19976230181
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