Reaction of {η5 -C5Me5)MoCl 4 with a 10-fold excess of LiBH4 followed by thermolysis with excess BH3·THF in toluene led to the formation of two oxamolybdaborane clusters, (η5-C5Me 5Mo)2B5(μ3OEt)H6R (2, R = H; 3, R = n-BuO). Clusters 2 and 3 have been characterized by 1H, 11B, and 13C NMR spectra and X-ray crystal structure determinations. 2 and 3 are notable examples of oxametallaborane compounds where oxygen is contiguously bound to both the cluster metal (molybdenum) and the boron atom. © 2009 American Chemical Society..

Sundargopal Ghosh

Department Of Chemistry

Babu Varghese

BORON ATOMS

CLUSTER METALS

NMR spectrum

Structural characterizations

X-ray crystal structures

boron

Boron Compounds

Molybdenum

Nuclear magnetic resonance spectroscopy

Oxygen

toluene

Crystal Structure

IIT Madras is a public technical and research university located in Chennai, Tamil Nadu. Founded in 1959, it is recognised as an Institute of National Importance.

IIT Madras has been ranked as the top engineering institute in India for four years in a row by the National Institutional Ranking Framework of the MHRD

It currently offers undergraduate, postgraduate and research degrees across 16 disciplines in Engineering, Sciences, Humanities and Management. About 596 faculty belonging to science and engineering departments and centres of the Institute are engaged in teaching, research and industrial consultancy.

IIT Madras

Organometallics

The thermolysis of arachno-1 [(Cp*Ru) 2 (B 3 H 8 )(CS 2 H)] in the presence of tellurium powder yielded a series of ruthenium trithia-borinane complexes: [(Cp*Ru) 2 (η 1 -S)(η 1 -CS){(CH 2 ) 2 S 3 BH}] 2, [(Cp*Ru) 2 (η 1 -S)(η 1 -CS){(CH 2 ) 2 S 3 B(SMe)}] 3, and [(Cp*Ru) 2 (η 1 -S)(η 1 -CS){(CH 2 ) 2 S 3 BH}] 4. Compounds 2-4 were considered as ruthenium trithia-borinane complexes, where the central six-membered ring {C 2 BS 3 } adopted a boat conformation. Compounds 2-4 were similar to our recently reported ruthenium diborinane complex [(Cp*Ru){(η 2 -SCHS)CH 2 S 2 (BH 2 ) 2 }]. Unlike diborinane, where the central six-membered ring {CB 2 S 3 } adopted a chair conformation, compounds 2-4 adopted a boat conformation. In an attempt to convert arachno-1 into a closo or nido cluster, we pyrolyzed it in toluene. Interestingly, the reaction led to the isolation of a capped butterfly cluster, [(Cp*Ru) 2 (B 3 H 5 )(CS 2 H 2 )] 5. All the compounds were characterized by 1 H, 11 B{ 1 H}, and 13 C{ 1 H} NMR spectroscopy and mass spectrometry. The molecular structures of complexes 2, 3, and 5 were also determined by single-crystal X-ray diffraction analysis. © 2019 by the authors.

Fulltext

Inorganics

Synthesis of trithia-borinane complexes stabilized in diruthenium core: [(Cp*Ru) 2 (η 1 -S)(η 1 -CS){(CH 2 ) 2 S 3 BR}] (R = H or SMe)

In an attempt to expand the library of M 2 B 5 bicapped trigonal-bipyramidal clusters with different transition metals, we explored the chemistry of [Cp*WCl4] with metal carbonyls that enabled us to isolate a series of mixed-metal tungstaboranes with an M 2 [B 4 M'] [M =W; M' = Cr(CO) 4 , Mo(CO) 4 , W(CO) 4 ] core. The reaction of in situ generated intermediate, obtained from the low temperature reaction of [Cp*WCl 4 ] with an excess of [LiBH 4 ·thf], followed by thermolysis with [M(CO) 5 ·thf] (M = Cr, Mo and W) led to the isolation of the tungstaboranes [(Cp*W) 2 B 4 H 8 M(CO) 4 ], 1-3 (1: M = Cr; 2: M = Mo; 3: M = W). In an attempt to replace one of the BH-vertices in M 2 B 5 with other group metal carbonyls, we performed the reaction with [Fe 2 (CO) 9 ] that led to the isolation of [(Cp*W) 2 B 4 H 8 Fe(CO) 3 ], 4, where Fe(CO) 3 replaces a [BH] core unit instead of the [BH] capped vertex. Further, the reaction of [Cp*MoCl 4 ] and [Cr(CO) 5 ·thf] yielded the mixed-metal molybdaborane cluster [(Cp*Mo) 2 B 4 H 8 Cr(CO) 4 ], 5, thereby completing the series with the missing chromium analogue. With 56 cluster valence electrons (cve), all the compounds obey the cluster electron counting rules. Compounds 1-5 are analogues to the parent [(Cp*M) 2 B 5 H 9 ] (M= Mo and W) that seem to have generated by the replacement of one [BH] vertex from [(Cp*W) 2 B 5 H 9 ] or [(Cp*Mo) 2 B 5 H 9 ] (in case of 5). All of the compounds have been characterized by various spectroscopic analyses and single crystal X-ray diffraction studies. © 2019 by the authors.

Synthesis, structures and chemistry of the metallaboranes of group 4-9 with M 2 B 5 core having a cross cluster M-M bond

Dimetallaoctaborane(12) of Ru, Co, and Rh have been well-characterized by a range of spectroscopic techniques and X-ray diffraction studies. Thus, reinvestigation of the Ir-system became of interest. As a result, a slight modification in the reaction conditions enabled us to isolate the missing Ir analogue of octaborane(12), [(Cp*Ir)2B6H10], 1. Compound 1 adapts a geometry similar to that of its parent octaborane(12) and Ru, Co, and Rh analogues. In [M2B6H10+x](M = Ru, x = 2; M = Co and Rh, x = 0), there exist two M-H-B protons. However, a significant difference observed in [(Cp*Ir)2B6H10] is the presence of two Ir-H instead of Ir-H-B protons that eventually controls the reactivity of this molecule. For example, unlike [M2B6H10](M = Co or Rh), the Ir-analogue does not react with metal carbonyl compounds or [Au(PPh3)Cl]. Along with 1, a closo trimetallic 8-vertex iridaborane [(Cp*Ir)3B5H4Cl], 2 was also isolated. Additionally, from another reaction, 12-vertex closo iridaboranes [(Cp*Ir)2B10Hy(OH)z], 3a and 3b (3a: y = 12, z = 0; 3b: y = 8, z = 2), have also been isolated. Further, density functional theory calculations were performed to gain useful insight into the structure and stability of these compounds. © 2017 American Chemical Society.

Inorganic Chemistry

Synthesis, Chemistry, and Electronic Structures of Group 9 Metallaboranes

In an objective to synthesize metallaheteroboranes containing heavier chalcogen atoms, we performed the reaction of dimetallaborane analogues of pentaborane(9) with various chalcogen sources. As a result, the thermolysis of nido-[1,2-(Cp∗RuH)2B3H7], 1 (Cp∗ = η5-C5Me5) with mixture of S and Se powder was carried out, that led to the isolation of half sandwich dimetallaheteroborane arachno-[(1,2-Cp∗Ru)2B2H6S2], 2. On the other hand, the reaction of nido-1 with diorganyldichalcogenide ligands, [Ph2E2] afforded chalcogen bridged half sandwich complexes [(2,3-Cp∗Ru)2B3H6(μ-η1-EPh)], 4a-c (4a: E = S; 4b: E = Se and 4c: E = Te). Compound 2 can be derived from a closo-snub disphenoid by removing a 5-connect vertex followed by the removal of a 3-connect vertex. Compound 4a-c can be described as nido-square pyramidal structures, isoelectronic and isostructural with nido-1. All the compounds have been characterized by mass spectrometry, 1H, 11B and 13C spectroscopy. Further, the geometry of compounds 2, 3, 4b and 4c were unequivocally established by crystallographic analysis. © 2014 Elsevier B.V. All rights reserved.

Journal of Organometallic Chemistry

Diruthenium analogues of Hexaborane(12) and Pentaborane(9): Synthesis and structural characterization of [(1,2-Cp∗Ru)2B2H6S2] and [(2,3-Cp∗Ru)2B3H6(μ-η1-EPh)], (E = S, Se and Te) (Cp∗ = η5-C5Me5)

Building upon our earlier work on low-boron containing molybdaborane arachno-[Cp∗Mo(CO)2B3H8], 1 we continue to investigate the reactivity of the same system with group 8 metal carbonyl compounds. As a result, thermolysis of arachno-1 in presence of [Ru3(CO)12] led to the formation of neutral heterometallic ketenylidene cluster [Cp∗Mo(CO)2(μ-H)Ru2(CO)6(μ3-É1-CCO)], 2, in which the triply bridged ketenylidene fragment (CCO) is lying perpendicular to the plane of the metal triangle (Ru-Mo-Ru). In addition to the formation of cluster 2, the reaction also yielded a semi-interstitial boride cluster [Cp∗Mo(CO)2{Ru(CO)3}4B], 3 and a known bimetallic cluster [Cp∗Mo(CO)3]2, 4 in moderate yields. The geometry of 3 can be described as a square pyramidal, in which the boron atom caps the square face formed by three Ru and one Mo atoms respectively. All the new compounds have been characterized by multinuclear NMR spectroscopy, IR spectroscopy and mass spectrometry. In addition to these, the solid state structure of 2 and 3 were unequivocally established by single crystal X-ray diffraction analysis. © 2015 Elsevier B.V.

Neutral heterometallic cluster containing ketenylidene ligand: [Cp∗Mo(CO)2(μ-H)Ru2(CO)6(μ3-É1-CCO)] (Cp∗ = É5-C5Me5)

Private final consumption expenditure, price indices

Journal of Public Economics

2006 Index Volume 90

Journal of the American Chemical Society

Synthesis and Characterization of the Octahydrotriborate Complexes Cp*V(B3H8)2and Cp*Cr(B3H8)2and the Unusual Cobaltaborane Cluster Cp*2Co2(B6H14)

Angewandte Chemie International Edition

Synthesis and Structure of 14- and 15-Vertex Ruthenacarboranes

Pediatric Asthma

of Childhood Asthma 19

Unusual open eight-vertex oxamolybdaboranes: Structural characterizations of (η5-C5Me5Mo)2B 5(μ-OEt)H6R (R = H and n-BuO)

Journal	Organometallics
ISSN	02767333
Open Access	No