First Pentanuclear Molybdenum Iodide Cluster (Bu<inf>4</inf>N)[Mo<inf>5</inf>OI<inf>13</inf>]: Synthesis and Structure

Abstract: The first iodide cluster of molybdenum with the metal cage in the form of a tetragonal pyramid (Bu4N)[Mo5OI13]·THF (I) and cocrystallizate (Bu4N){[Mo5OI13]0.9[Mo6I14]·THF (II) are synthesized for the first time by heating a LiI–I2–Mo mixture in a temperature range of 300–400°С followed by the extraction of the product. Complexes I and II are studied by X-ray diffraction analysis (CIF files CCDC nos. 2063029 (I) and 2063030 (II)). The molybdenum atoms in [Mo5OI13]– form a square pyramid with Mo–Mo distances of 2.67 Å between the basal molybdenum atoms and the Mo–Mo distances equal to 2.72 Å between the apical and basal molybdenum atoms. The oxygen atom is coordinated to the pyramid base (Mo–μ4-O 2.10 Å). The cluster anion [Mo5OI13]– can be presented as the octahedral cluster anion [Mo6I14]2– in which the position of the {MoI}– fragment (d0, 6e) is occupied by the isoelectronic oxygen atom (s2p4, 6e). In the structure of compound II, the [Mo5OI13]– and [Mo6I14]2– cluster anions occupy close atomic positions

Thiocyanate Coordination to the {Ta<inf>6</inf>I<inf>12</inf>}²⁺ Cluster. Preparation and Crystal Structure of [K(Dibenzo-24-Crown-8)(CH<inf>3</inf>COCH<inf>3</inf>)]<inf>2</inf>(Ph<inf>4</inf>P)<inf>2</inf>[Ta<inf>6</inf>I<inf>12</inf>(NCS)<inf>6</inf>]

© 2020, Pleiades Publishing, Ltd. The reaction of Ta6I14 with KNCS in acetonitrile in the presence of 24-dibenzo-crown-8 leads to dissolution of the tantalum iodide cluster to form the [Ta6I12(NCS)6]4− complex. By evaporation of the solution with the subsequent treatment of the precipitate with acetone and PPh4Br, dark green single crystals of the composition [K(C24H32O8)(CH3COCH3)]2(Ph4P)2[Ta6I12(NCS)6] CH3COCH3(1) are obtained with a yield of 29%. The product is characterized by elemental analysis, IR, and mass spectra. The crystal structure is determined by the X-ray diffraction analysis

PROPIOLATE CLUSTER COMPLEXES (Bu<inf>4</inf>N)<inf>2</inf>[Mo<inf>6</inf> X <inf>8</inf>(OOC–C≡CH)<inf>6</inf>] (X = Br, I)

Abstract: Two new cluster complexes (Bu4N)2[Mo6X8(OOC–C≡CH)6] (1) (X = Br) and (2) (X = I) are synthesized by the reaction of (Bu4N)2[Mo6X8(OOCCH3)6] (X = Br, I) with HOOC–C≡CH propiolic acid, their crystal structures are determined, and the luminescent properties are studied for powder samples at different temperatures. According to X-ray crystallographic data, molybdenum atoms are monodentately coordinated by oxygen atoms of the carboxyl group at Mo–O distances of 2.108(2)-2.121(16) Å. The propiolate complexes are characterized by electrospray mass spectrometry, 1Н and 13С NMR, elemental analysis, and IR spectroscopy. [Figure not available: see fulltext.

Synthesis and Characterization of the New Cluster Complex {Mo<inf>3</inf>S<inf>4</inf>} with the Hemilabile Phosphine-Selenoether Ligand

Abstract: The reaction of [Mo3S4(Tu)8(H2O)]Cl4·4H2O (Tu is thiourea) with (PhCH2CH2)2-PCH2CH2SeC5H11) (PSe) followed by purification on a chromatographic column packed with silica gel using a saturated solution of KPF6 in acetone as an eluent results in the formation of [Mo3S4Cl3(PSe)3]PF6 (I) in a yield of 44%. Compound I is characterized by X-ray diffraction analysis, 1H, 31P{1H}, and 77Se NMR spectroscopy, IR spectroscopy, UV-Vis spectroscopy, cyclic voltammetry, and electrospray ionization mass spectrometry. Several species differed in the coordination mode of three PSe ligands, which can bind to molybdenum via one (phosphorus) or two (phosphorus and selenium) donor atoms, are formed in a solution of compound I at room temperature. This behavior is not observed for the compounds similar in structure with PS ligands of an analogous type. Complex I demonstrates a higher catalytic activity than its analogue with the PS ligand in the reduction of nitrobenzene to aniline under the action of diphenylsilane