Darstellung, Infrarotspektren und Strukturen einiger dimerer und polymerer Oxochloro- und Oxooxalato-isothiocyanato-Komplexe des Molybdän(V).

Abstract

Oxomolybdates(V), IR, Crystal StructureThe crystal structure of (PyH)2(Mo204Cl4) Beim thermischen Abbau beträgt der Gewichtsverlust bis 210 °C etwa 8,5%, was einem Wassergehalt von 1,5 mol H2O pro Metallatom entspricht. Die Verbindung ist diamagnetisch (temperaturunabhängig).•Da das IR-Spektrum der von uns erhaltenen Verbindung mit dem für den vierkernigen Komplex angegebenen Spektrum übereinstimmt, bestehen an der Identität beider Substanzen kaum Zweifel. Wie schon kurz mitgeteilt 3 , stellten wir u.a. aufgrund der Messung der Gitterkonstanten entlang der Nadelachse einen neuen Strukturvorschlag für 1 auf. Die Fortführung der Strukturaufklärung bestätigte dieses Modell; die Genauigkeit der Strukturbestimmung ist aber durch Verzwilligungen und Fehlordnungen in allen untersuchten Kristallen stark eingeschränkt.Kristalldaten von 1: a = 31,61(9)1, V = 432,7 A 3 , 6= 31,92(9) Ä, Q = 1,88 g/cm c = 4,11(1) Ä, Z= 16.

Triply bridged binuclear thiolate complexes of oxomolybdenum(V). Synthesis of [Mo2O2(SR)6Z]- (Z = OR', SR', NR'2) and crystal structures of (Et4N)[Mo2O2(SCH2CH2O)2Cl3], (Et4N)[Mo2O2(SCH2CH2O)3Cl], and (Pr3NH)[Mo2O2(SCH2CH2O)3(SCH2CH2OH)]

“…There is no significant difference in length between the terminal Mo-S (mean 2.384 Á) and Mo-Cl (mean 2.386 Á) bonds, although the Mo-S distances show greater variation. The terminal Mo-S bond lengths observed here are slightly less than other comparable values for OMov-thiolate coordination, namely, 2.41 ± 0.01 Á26 in [MoO(SPh)4]",9 29 The mean length for the Mo-bridging thiolate (SI) bond is 2.481 Á, an elongation of 0.10 Á over the comparable Mo-terminal thiolate bond length. This elongation is of similar magnitude to that measured in complexes of other metals containing both terminal and bridging thiolate ligands.30,31 The six Mo-OS 1 distances are quite variable, which is consistent with the weaker bonding ascribed to this interaction.…”

Novel Methanol‐Containing Oxomolybdate(V) Complexes: Synthesis and Structural Characterisation of Intermediates in the Formation of {Mo2O4}2+ Clusters from [MoOCl4(H2O)]– and [MoOBr4]– Precursors

“…The absorption at 883 cm –1 in the infrared spectrum of (PyH)[MoOBr 4 ] strongly indicates a polymeric chain structure via Mo=O ··· Mo interactions 13,41. Support for this also comes from the infrared spectrum of (PyH) 2 ‐[Mo 2 O 4 Cl 4 ] · 3H 2 O whose X‐ray structure reveals chains of dinuclear [Mo 2 O 4 Cl 4 ] 2– ions linked via Mo=O ··· Mo interac‐tions 42. The Mo–O stretching band for (PyH) 2 [Mo 2 O 4 Cl 4 ] · 3H 2 O is observed at 888 cm –1 .…”

Modeling the Formation of Molybdenum Oxides from Alkoxides: Crystal Structures of [Mo4O4Cl4(μ2-OEt)4(HOEt)2(μ3-O)2] and [PPN]+[Et3NH]+[Cl2(O)Mo(μ2-O)2Mo(O)Cl2]2-

“…The structure of such an anion was reported previously. Analysis of the disordered crystals of the trihydrated pyridinium salt (prepared by heating a solution of [C 5 H 6 N] 2 [OMoCl 5 ] in 96% ethanol and subsequent addition of dioxane) discloses pseudo-six-coordinate Mo atoms created by the short MoO··· Mo interactions between the anions stacked along the short c axis of the orthorhombic unit cell. A more precise determination has been performed on the same anion in the form of a solvated tetraphenylarsonium salt (synthesized by the reaction of OMoCl 3 ·SMe 2 with [Ph 4 As]Cl in wet CH 2 Cl 2 ).…”