Silver and Copper Complexes with closo-Polyhedral Borane, Carborane and Metallacarborane Anions: Synthesis and X-ray Structure (original) (raw)
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Dalton Transactions, 2008
The complexes [Cu(Bm Me)] 3 •0.77C 4 H 8 O (1), [(Bm Me)Ag(PPh 3)] (2) and [M{k 3-H(m-H)B(tiaz) 2 }(PPh 3)] (M= Cu (3), Ag (4); Bm Me = bis(2-mercapto-1-methylimidazolyl)borate, H 2 B(tiaz) 2 = dihydrobis(2-mercaptothiazolyl)borate) have been prepared and characterised by X-ray crystallographic and spectroscopic methods. The presence of M ◊ ◊ ◊ H-B interactions in these species has been investigated using infrared spectroscopy and crystallography. In [Cu(Bm Me)] 3 , the triangular array of three trigonal-planar copper atoms is coordinated by three chelating and bridging (Bm Me)ligands, and has an unusual, highly unsymmetrical arrangement with one short Cu-Cu distance; this is the first structurally authenticated Bm Me complex with a nuclearity greater than two. In complexes 2-4, the metal atom is found in a distorted trigonal-planar geometry, bound by a terminal phosphine ligand and two sulfur atoms of a chelating ligand, supplemented by an M ◊ ◊ ◊ H-B interaction, which appears to be a common feature in the coordination chemistry of the (Bm Me)and [H 2 B(tiaz) 2 ]ligands; compounds 1-4 are the first reported complexes of copper(I) and silver(I) with any bis(2-mercaptoimidazolyl)borate ligand or with H 2 B(tiaz) 2 .
Silver(I) and Copper(I) Complexation with Decachloro-Closo-Decaborate Anion
Crystals, 2020
A series of complexation reactions of silver(I) and copper(I) in the presence of a polyhedral weakly coordinating [B10Cl10]2− anion has been carried out. The effect of the solvent and the presence of Ph3P on the composition and structure of the reaction product were studied. Eight novel complexes were obtained and characterized by 11B Nuclear magnetic resonance, Infra-Red, and Raman spectroscopies as well as powder and single-crystal X-ray diffraction techniques. The [B10Cl10]2− anion demonstrated weaker coordinating ability towards coinage metals than [B10H10]2− at similar reaction conditions. The [B10Cl10]2− anion remains unreacted in the copper(I) complexation reaction, while in the absence of competing ligands, we obtained the first complexes containing decachloro-closo-decaborate anion directly coordinated by the metal atom. The bonding between metal atoms and the boron cluster anions was studied using the atomic Hirshfeld surfaces. Besides edge and face coordination of the pol...
Journal of the American Chemical Society, 1977
A series of air-stable crystalline cobaltaboranes has been isolated from the reaction of Na+BsHg-, CoC12, and Na+C5H5in THF below -20 OC. The major products were red 2-(qs-C5H5)CoB4H8 (an analogue of B5H9) and the known orange complex 1,3-cyclohexadienecobalt(II) cyclopentadiene, (C&)CO(C~H~). The pyrolysis of 2-(q5-C5H5)CoB4H8 at 200 OC produced yellow 1-(q5-C5H5)CoB4Hs, cobalt moving to the apex position. The other structurally characterized products were: red 5-(q5-C5Hs)CoB9H13 (a B I~H 1 4 analogue); violet 1,2-(q5-CsH5)2Co2B4H6 and its 3-and 4-cyclopentyl derivatives, for which octahedral structures were assigned; brown ~,~,~-( ? S -C~H S )~C O~B~H~, octahedral; yellow (q5-C5H5)3-Co3B4H4, a capped octahedron; green (q5-C5Hs)4C04B4H4, a D2,j dodecahedron, and red b(2,3)-l,3-C3H4-1,7,2,3-(q5-C~H~)~C O~C Z B~H~, a derivative of the known triple-decked sandwich metallocarborane 1,7,2,3-(q5-C5H5)2C02C2BjH5, in which the central C2B3 ring is fused on an edge to a cyclopentadiene ring. The compounds were characterized from I L B and IH pulse Fourier Transform NMR, unit-and high-resolution mass spectra, and infrared spectra, supported by x-ray diffraction data on (C5H5)CoB9Hl3, (CSH5)3C03B3H5, ( C~H S )~C O~B~H~, and p-C3H4-(C5H5)2C02C2B3H3, and an earlier x-ray study of ~-( C~H~) C O B~H~. 4 skeletal valence electrons, closo systems (polyhedra with all faces triangular) having 2n + 2 electrons, and 2n-electron systems which are electron hyperdeficient and normally adopt capped polyhedral geometry. All of these species contain formal cobalt(II1) as shown by the normal N M R spectra, which are indicative of diamagnetic spin states.
Chemistry - A European Journal, 1995
The structure of the dl-Ti(BH& complex is studied by means of ab initio UHF calculations including correlation energy at the MP2 level. Twenty structures which differ by the coordination mode of the BH4-ligands are optimized through an analytical gradient method, using the double-c basis set I. In agreement with the experimental data, the C3h (73, q3, v3) structure is found to be the most stable, a result which is confirmed by calculations with the extended basis set 11. The geometry of the absolute minimum and the energy ordering of the other structures are rationalized through electron counting around the metal atom. Average bond lengths are given for each coordination mode, and a mechanism for exchange between bridging and terminal hydrogen atoms is proposed, with an activation energy of only 5.1 kcal/mol (basis set 11). The coordination mode of the tetrahydroborato ligand is a fascinating problem since it can bind a transition metal with one (vl), two (q2), or three (v3) bridging hydrogens (Hb).] Depending on the way it is bound to the metal, it behaves as a 2-, 4-, or 6-electron donor, respectively.2 Therefore, the coordination mode has been often related to the 18-electron rule. As an example the tetrahydroborato ligand is bound in an q1 fashion in the Cu-(BH4)(PMePh2)3 complex,3 in which the total number of electrons is 10 (Cu) + 3x2 (phosphines) + 2 (BH4-) = 18; the loss of a phosphine group [ C U (B H~) (P P~~)~]~ entails a change in the coordination mode of BH4-(7'-q2) in order to keep the 18electron count. When more than one tetrahydroborato group is bound to the metal, symmetry restrictions must be taken into account to obtain the proper electron c o~n t .~J On theother hand, the ideal electron number may be different from 18 in paramagnetic complexes: for instance, it is 16 in high-spin d2 complexes and 17 in d1 ones. These two points having been noted, the basic relationship between the coordination mode and the number of electron around the metal still applies in rather complicated systems such as those we studied previously by ab initio calculations [M(BH&(PH&; M = V,6 S C ,~ Ti*].
New Trinuclear Complexes of Group 6, 8, and 9 Metals with a Triply Bridging Borylene Ligand
Chemistry - A European Journal, 2016
Trinuclear complexeso fg roup 6, 8, and 9t ransition metals with a(m 3-BH) ligand [(m 3-BH)(Cp*Rh) 2 (m-CO)M'(CO) 5 ], 3 and 4 (3:M ' = Mo; 4:M ' = W) and 5-8, [(Cp*Ru) 3 (m 3-CO) 2 (m 3-BH)(m 3-E)(m-H){M'(CO) 3 }] (5:M ' = Cr,E = CO; 6:M ' = Mo, E = CO; 7:M ' = Mo, E = BH; 8:M ' = W, E = CO), have been synthesized from the reaction between nido-[(Cp*M) 2 B 3 H 7 ](nido-1:M = Rh; nido-2:M = RuH, Cp* = h 5-C 5 Me 5)a nd [M'(CO) 5 •thf] (M' = Mo and W). Compounds 3 and 4 are isoelectronic and isostructuralw ith [(m 3-BH)(Cp*Co) 2 (m-CO)M'(CO) 5 ], (M' = Cr,M oa nd W) and [(m 3-BH)(Cp*Co) 2 (m-CO)(m-H) 2 M''H(CO) 3 ], (M'' = Mn and Re). All compounds are composed of ab ridging borylene ligand (BÀH) that is effectively stabilized by at rinuclearf ramework. In contrast, the reactiono fnido-1 with [Cr(CO) 5 •thf] gave [(Cp*Rh) 2 Cr(CO) 3 (m-CO)(m 3-BH)(B 2 H 4)] (9). The geometry of 9 can be viewed as ac ondensed polyhedron composed of [Rh 2 Cr(m 3-BH)] and [Rh 2 CrB 2 ], atetrahedral andasquare pyramidal geometry,respectively.T he bonding of 9 can be considered by using the polyhedralf usion formalism of Mingos. Allc ompounds have been characterized by using differents pectroscopics tudies and the molecular structures were determined by using single-crystal X-ray diffraction analysis.
Low-Coordinate Boride Ligands: A True Trimetalloborane
Angewandte Chemie International Edition, 2009
The development of boron-metal chemistry has roughly tracked that of carbon-metal (i.e., organometallic) chemistry, beginning with singly bound boryl (MBR 2 ) complexes, then doubly bound bridging (M 2 BR) and terminal (MBR) borylene complexes. In other words, the conceptual replacement of R groups from a borane BR 3 with metal fragments has been a gradual process, and full replacement to form a trimetalloborane is a lingering challenge.
Side-on coordination of boryl and borylene complexes to cationic coinage metal fragments
Chem. Sci., 2015
3 )}] (2) can be functionalized via halide substitution reactions to afford isostructural complexes [(h 5 -C 5 H 5 )(OC) 2 Mn{m-B(R)(tBu)Au(PPh 3 )}] (R ¼ Ph, CCPh and NCS). It also reacts with coinage metal complexes [MCl(PPh 3 )] (M ¼ Au, Ag and Cu) in the presence of halide abstraction reagents to afford borylene-bridged heteromultinuclear complexes [{(h 5 -C 5 H 5 )(OC) 2 Mn} 2 {m 2 -B(tBu)} 2 M][BAr x 4 ] (M ¼ Au, Ag and Cu; Ar x ¼ 3,5-C 6 H 3 Cl 2 , 3,5-C 6 H 3 (CF 3 ) 2 ). Experimental characterization as well as computational studies revealed that these complexes are best viewed as transition metal borylene complexes side-on coordinated to monovalent coinage metal cations, thus representing the first boron analogs of Stone's alkylidyne-bridged multinuclear complexes. † Electronic supplementary information (ESI) available: Experimental; details of X-ray crystallographic and computational studies. CCDC 1033284-1033294. For ESI and crystallographic data in CIF or other electronic format see