Syntheses of Heteronuclear Molybdenum/Bismuth Alkoxides Stabilized by Organic Ligands

Abstract

Reaction of [((CH 3 )C 3 H 4 )Mo(CO) 2 (CH 3 CN) 2 Cl], 2, with [Bi(OEt) 3 ] x provides the heterotetranuclear complex [((CH 3 )C 3 H 4 )Mo(CO) 2 (µ-OEt) 3 Bi(µ-OEt) 2 Bi(µ-OEt) 3 Mo(CO) 2 ((CH 3 )-C 3 H 4 )], 3, in good yields. If 2 is reacted with [Bi(OCH 2 CH 2 OCH 3 ) 3 ] 2 , a dinuclear chloro alkoxide [((CH 3 )C 3 H 4 )Mo(CO) 2 (µ-κO,2κO′-OCH 2 CH 2 OCH 3 ) 2 (µ-Cl)BiCl], 4, is obtained, while pretreatment of 2 with AgBF 4 and subsequent reaction with [Bi(OCH 2 CH 2 OCH 3 ) 3 ] 2 leads to the chloride-free complex [((CH 3 )C 3 H 4 )Mo(CO) 2 (µ-κO,2κO′-OCH 2 CH 2 OCH 3 ) 3 Bi(thf)][BF 4 ], 6, with a Bi center surrounded by seven oxygen donors. All compounds have been characterized by NMR and IR spectroscopy as well as elemental analysis, and their crystal structures were determined by means of single-crystal X-ray diffraction. 3, 4, and 6 belong to the few compounds known (there is only one other precedent) where Mo and Bi centers are bridged by oxygen-containing ligands and can therefore be considered as cornerstones on the way to the synthesis of yet unknown molecular compounds with Mo-O-Bi functions resembling those occurring on the surface of nMoO 3 -Bi 2 O 3 catalysts.

Heterobimetallic Bi(III)−Ti(IV) Coordination Complexes: Synthesis and Solid-State Structures of BiTi4(sal)6(μ-OiPr)3(OiPr)4, and the Cyclic Isomers Bi4Ti4(sal)10(μ-OiPr)4(OiPr)4 and Bi8Ti8(sal)20(μ-OiPr)8(OiPr)8

“…In the case of 1 and 2 , this bridge occurs between a titanium and bismuth atom, whereas in the case of 3 , the bridging alkoxides are associated exclusively with the bismuth atoms. Only a handful of such complexes showing bridging alkoxide interactions between bismuth and another metal have been reported. ,,,, Additionally, there has been no spectroscopic or crystallographic evidence for the interaction of an alkoxide ligand with a bismuth center in any of the other similar heterometallic complexes that we have produced that contain both salicylate and alkoxide ligands, the latter always previously being associated with the transition metal portion of the molecule. In this case, it seems plausible that the formation of the alkoxide interaction between the two metal species ( 1 and 2 ) or between the adjacent bismuth centers ( 3 ) is due to the bismuth attempting to satisfy its high Lewis acidity, which may be enhanced by the apparent electron withdrawing effects of the salicylate ligands.…”

Molybdenum η3-Allyl Dicarbonyl Complexes as a New Class of Precursors for Highly Reactive Epoxidation Catalysts with tert-Butyl Hydroperoxide

“…[10][11][12][13][14][15][16][17] Since the discovery of pseudooctahedral molybdenum(II) complexes of the type [Mo(η 3 -allyl)X(CO) 2 (CH 3 CN) 2 ] (X ) halide) in 1968, 18 a series of derivatives containing the {Mo(η 3 -allyl)(CO) 2 } + moiety has been easily prepared by substitution of the labile nitrile ligands and/or the anion X. 2,12,14,18,[19][20][21][22][23][24][25][26][27] In particular, compounds of the type [Mo(η 3 -allyl)X(CO) 2 (N-N)], where N-N ) 2,2′-bipyri- dine or 1,10-phenanthroline, were found to possess some air and water tolerance. 28,23 These compounds have been successfully used as catalyst precursors for imine aziridination, 29 oxidation of triphenylphosphine with molecular oxygen, 30 or as catalysts for allylic alkylations.…”

“…The availability of suitable starting materials has always been of considerable importance to the synthetic chemist. η 3 -Allyl dicarbonyl complexes of Mo and W play an important role in both coordination chemistry − and catalytic organic transformations, and their reactivity depends on the nature of the ligands completing the coordination sphere. − Since the discovery of pseudooctahedral molybdenum(II) complexes of the type [Mo(η 3 -allyl)X(CO) 2 (CH 3 CN) 2 ] (X = halide) in 1968, a series of derivatives containing the {Mo(η 3 -allyl)(CO) 2 } + moiety has been easily prepared by substitution of the labile nitrile ligands and/or the anion X. ,,,,− In particular, compounds of the type [Mo(η 3 -allyl)X(CO) 2 (N−N)], where N−N = 2,2‘- bipyridine or 1,10-phenanthroline, were found to possess some air and water tolerance. , These compounds have been successfully used as catalyst precursors for imine aziridination, oxidation of triphenylphosphine with molecular oxygen, or as catalysts for allylic alkylations. − Recent studies have revealed that complexes [Mo(η 3 -C 3 H 5 )X(CO) 2 (CH 3 CN) 2 ] act as single component initiators for ring-opening metathesis polymerization of norbornene and polymerization of terminal acetylenes and catalyze the oligomerization of Ph(C⋮C) n Ph ( n = 1, 2) …”

The structural characterization of the first mononuclear alkoxide cation: Isolation and X-ray study of [Mo(OMe)5(CH3CN)]Bi2Cl7

“…Attempts to prepare stable heterometallic complexes derived from these two metals have been made using aliphatic alkoxides or alkoxyalkoxides [4], and also applying different alkoxide and functional alkoxide complexes of bismuth in reaction with cyclopentadienyl or allyl-substituted molybdenum carbonyl compounds [1]. The latter approach provided successfully several heterometallic species such as Cp 2 Mo(l-OEt) 2 Bi(OEt) 2 Cl [5], CH 3 C 3 H 4 Mo(CO) 2 (l-OEt) 3 Bi(OEt) 2 (l-OEt) 3 Mo(CO) 2 CH 3 C 3 H 4 [6], etc. In the present communication, we report preliminary results of the study of interaction of molybdenum oxomethoxide with anhydrous bismuth chloride, leading to the formation of a salt involving an extremely unusual solvated alkoxide cation and heptachlorodibismutate anion.…”

“…The cations and anions form chains along the c-axis in the structure (Fig. 2 [14] or [(CH 3 C 3 H 4 )Mo(CO) 2 (l 2 ,g 2 -OC 2 H 4 OMe) 3 Bi(thf)] + [6] stabilized by large, highly symmetric anions such as W 6 O 2À 19 and BF À 4 , respectively. It is important to note that interaction of an oxoalkoxide compound with a Lewis acidic metal chloride leads to the formation of a heterometallic complex free from oxo-ligands.…”