Directed Synthesis of [Mo₃S₁₃]²⁻, an Isolated Cluster Containing Sulfur Atoms in Three Different States of Bonding

Abstract

The directed synthesis of cluster-compounds is a current problem in transition metal chemistry"'. For the subgroup VI metals (Mo and W) with d" configuration, cluster types are expected to be dumb-bell shaped (in the case where n= I), triangular ( n = 2), tetrahedral (n = 3) and octahedral (n = 4) (here n also indicates the number of metal-metal bonds originating from each metal atom). Recently, the first binary species with n = l , uiz [ M O~( S , )~]~-, has been isolated in the form of its ammonium salt [']. We now report the synthesis of the homologous cluster with n = 2 from a solution containing Mo". Hitherto, the transition metal sulfur clusters, as model compounds of bioinorganic interest, could only be obtained by unusual reactions from unusual reactants and often only in lowThe dark-red, crystalline compound (NH4)2[Mo3S(S2)6]. the same length [']. As expected, the Mo-Mo distances (2.67 A) are somewhat shorter in ( I ) and the coordination number of molybdenum is again 9[41.The Si-ligands favor high coordination numbers and are suitable for stabilizing metal clusters, since an optimum shielding of the metal atoms is achieved through the high coordination numbers arising due to the small MSz-angle. From the above mentioned scheme the existence of the homologouscould be predictedL6! Obviously the stability of these compounds is also connected with the occurrence of only tricoordinated sulfur in the central units ({ M o~S ( S Z )~} (in (1 )) and probably {Mo4S4}L6l (for the low reactivity cf. [31). Experimental30ml of saturated ammonium polysulfide is added to a reddish brown solution of 2.Og of (NH4)6M07024.4HZ0 and 1.5g of NHzOH.HCl in 30ml water. The resulting solution is warmed to 40-50°C for 1 h, then cooled to room temperature, filtered, and the filtrate heated at ca. 90°C for 3-4 h.Dark-red crystals of (1) Angew. Chem. 87, 363 (1975); Angew. Chem. Int. Ed.Engl. 14, 322 (1975). [4] Details of the X-ray structure analysis will be published later. The water content follows from elemental analysis and T G but could not be finally confirmed by structure analysis.[S] Because of thecoupling in the ring system thedesignation of the vibrations is only approximate.[6] The central unit has already been found in [(C5H5)MoSI4 (cf. [3]). Optically Active Polyvinyl Compounds with Chirality in the Main Chain[**]By Giinter W u g Karl Zabrocki, and Johann Hohn"]We recently described a method for the preparation of synthetic polymers having cavities containing functional groups in a definite steric arrangement[" ' I. Functionally substituted polymerizable vinyl compounds were bound to a suitable chiral template molecule and then copolymerized under stringent crosslinking conditions. After removal of the template from the polymer the latter contains microcavities, whose shape is largely determined by the shape of the template, and within which the functional groups are in a fixed stereochemistry corresponding to the structure of the template. Such polymers can be used for the resolution of racemates ['].In order to c...

Photogeneration of Hydrogen from Water by Hybrid Molybdenum Sulfide Clusters Immobilized on Titania

“…The chemical composition of each peak in the scan mode was assigned by comparing the experimental isotope pattern with that calculated using the MassLynx 4.1 program. [36] according to a procedure described in the literature. [37] (CO 2 Me) 2 bpy was obtained by the oxidation of 4,4'-Me 2 -2,2'-bpy (4,4'-dimethyl-2,2'-bipyridine) followed by esterification of 4,4'-(CO 2 H) 2 -2,2'-bpy (2,2'-bipyridine-4,4'-dicarboxylic acid).…”

“…(Bu 4 N) 2 [Mo 3 S 7 Br 6 ] was prepared from (NH 4 ) 2 [Mo 3 S 13 ]·2 H 2 O [36] according to a procedure described in the literature. [37] (CO 2 Me) 2 bpy was obtained by the oxidation of 4,4'-Me 2 -2,2'-bpy (4,4'-dimethyl-2,2'bipyridine) followed by esterification of 4,4'-(CO 2 H) 2 -2,2'-bpy (2,2'bipyridine-4,4'-dicarboxylic acid).…”

Preparation and characterization of molybdenum sulfide supported on β-zeolites obtained from [Mo3S4(H2O)9]4+ precursor

“…A violet solid (30.2 g, 65% yield based on Mo) was collected as (NH 4 ) 2 Mo 3 S 13 Á2H 2 O. We checked that the FTIR spectrum (not shown) was consistent with that of [Mo 3 S 13 ] 2À published by Müller et al[10]. Á6H 2 O as a yellow-orange crystalline solid.…”

Extraordinary Selectivity of CoMo3S13 Chalcogel for C2H6 and CO2 Adsorption

“…In the case of the reactions of ammonium thiomolybdate with cobalt salts, catalysts with good activity in hydrodesulfurization (HDS) reactions can be obtained 9, 17. Here, we have investigated the use of Müller's polysulfide cluster (NH 4 ) 2 Mo 3 S 13 as a secondary well‐defined building unit in metathesis reactions with cobalt ions 18…”