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The interaction of the macrocycle (o,o′‐C6F4C6F4Hg)3 (1) containing three mercury centres with arylphosphonium salts ([Ph4P]Cl or [Ph4P]Br) yields halide complexes, [Ph4P]{[(o,o′‐C6F4C6F4Hg)3](η1:η1‐X)} (X=Cl, Br) having infinite polymer chain structure in the crystal. In both adducts, the halide anion is situated outside of the cavity of the three‐mercury anticrown 1 and bridged by two mercury centres of neighbouring anticrown moieties. At the same time, when mercuracycle 1 interacts with tetraalkylammonium salts ([nBu4N]Cl or [nBu4N]Br), then the discrete 1 : 1 complexes [nBu4N]{[(o,o′‐C6F4C6F4Hg)3](η3‐X)} (X=Cl, Br) of completely different structure are formed. In these halide complexes the anion is located inside the cavity of macrocycle 1 and coordinates the three mercury atoms symmetrically. The synthesized halide complexes [nBu4N]{[(o,o′‐C6F4C6F4Hg)3](η3‐X)} (X=Cl, Br) are the first example of complexes of the macrocycle 1 where it behaves as anticrown. [ABSTRACT FROM AUTHOR]

Abstract: The heating of the isomeric [1-(η6-1,4-Me2C6H4)-3-Cl-isonido-1,2,4-RuC2B8H9] (1) or [1-(η6-1,4-Me2C6H4)-6-Cl-isonido-1,2,4-RuC2B8H9] (2) complexes (i) in a 1,4-Me2C6H4 solution at 85 °C as well as (ii) in a melt at 165 °C afforded mixtures of isomeric isonido- and closo-ruthenacarboranes, which differ in the positions of the chlorine substituent and the carbon atoms in the cage ligand. Structures of all new isomeric complexes have been established on the basis of analytical and multinuclear NMR data and were characterized by single-crystal X-ray diffraction studies. Also presented are the results of the quantum chemical calculations for the ground and the transition states of the reaction (i), which proved to be basis for the suggestion of interconversion scheme for these isomers. [Copyright &y& Elsevier]

Abstract: Reactions of [3,3-(PPh3)2-3-Cl-3-H-3,1,2-closo-RuC2B9H11] (1) and its exo-nido isomer [exo-5,6,10-{Ru(Ph3P)2Cl}-5,6,10-(μ-H)3-10-H-7,8-nido-C2B9H8] (2) with NH4PF6 in methanol or ethanol solution followed by heating in the presence of an excess of phenylacetylene (3) affords a mixture of two isomeric closo species [3,3-{(1′-3′-η3):(5′,6′-η2)-ortho-C6H4PPh2CHC(Ph)CHCHPh}-8-(σ–CH,2-closo-RuC2B9H10] (4) and [3,3-{(1′-3′-η3):(5′,6′-η2)-ortho-C6H4PPh2CHC(Ph)CHCHPh}-4-(σ–CH,2-closo-RuC2B9H10] (5) in which boron vertexes in β- and α-sites with respect to the cage carbons bear the (E)–CHp. The X-ray diffraction study of 4 together with the multinuclear NMR data for 4 and 5 revealed that such an unusual η3:η2-phosphacarbocyclic ligand in both isomeric complexes is formed by specific insertion of the initially metal-bound PPh3 group into the chain of two alkyne molecules coupled in a “head-to-tail” fashion around the metal vertex. [Copyright &y& Elsevier]

Abstract: The room temperature reactions between [Rh2(η5-C5Me5)2Cl4] (1) and [K][7-R1-8-R2-7,8-nido-C2B9H10] (2a–d: a, R1 =R2 =H; b, R1 =R2 =Me; c, R1 =H, R2 =PhCH2; d, R1 =R2 =PhCH2) in solution of C6H6–EtOH mixture (4:1) to give [3-(η5-C5Me5)-1-R1-2-R2-3,1,2-closo-RhC2B9H9] (3a–d), respectively, have been shown to proceed through the formation of the first step ionic intermediates of the type [(η5-C5Me5)Rh(μ-Cl)3Rh(η5-C5Me5)][7-R1-8-R2-7,8-nido-C2B9H10] (4a–d). All ionic compounds 4a–d were isolated in the solid state and characterized by a combination of analytical, IR and multinuclear NMR data, including a single-crystal X-ray diffraction study of 4d. The structure of 3d (R1 =R2 =PhCH2), the first 12-vertex closo-type metallacarborane species bearing sterically demanding C,C′-dibenzylsubstituted carborane ligand, has also been determined by an X-ray crystallography. [Copyright &y& Elsevier]

Abstract: Reactions of [exo-nido-5,6,10-{Cl(Ph3P)2Ru}-5,6,10-(μ-H)3-10-H-7,8-R2-7,8-C2B9H6] (1, R=H; 2, R=Me) with the chiral (2S,4S)-2,4-bis(diphenylphosphino)pentane (3,S,S-bdpp) ligand proceed in benzene with replacement of both PPh3 ligands on the metal center with the diphosphine affording the chelate exo-nido complexes [exo-nido-5,6,10-{Cl(S,S-bdpp)Ru}-5,6,10-(μ-H)3-10-H-7,8-R2-7,8-C2B9H6] (7, R=H) and (8, R=Me), respectively. A relatively fast and irreversible rearrangement of 7 into its closo isomer [closo-3,3-(S,S-bdpp)-3-Cl-3-H-3,1,2-RuC2B9H11] (4) occurs in solution already at room temperature. On the contrary, exo-nido-to-closo conversion of 8 proceeds in benzene (or much faster in toluene) only on heating and yields 17-electron paramagnetic complex [closo-3,3-(S,S-bdpp)-3-Cl-1,2-Me2-3,1,2-RuC2B9H9] (9). All exo-nido- and closo-ruthenacarboranes obtained were characterized by a combination of analytical, multinuclear NMR or EPR spectroscopic data and, in addition, by X-ray diffraction studies of both dimethylated complexes 8 and 9. [Copyright &y& Elsevier]

Abstract: The [7-Me3N-nido-7-CB10H12] (1), after being treated with two molar equiv. of Proton Sponge, reacts with [(η4-C10H12)2Rh2(μ-Cl)2] (2) in benzene–ethanol solution affording two isomeric monocarbon (η-dicyclopentenyl)-closo-rhodacarborane complexes, differing in hapticity of the carbocyclic ligand, viz. [2,2-{(2′,3′-η2):(5′-η1)-C10H13}-1-(Me3N)-2,1-closo-RhCB10H10] (3) and [2-{(1′-3′-η3)-C10H13}-1-(Me3N)-2,1-closo-RhCB10H10] (4). Isomeric compounds 3 and 4 were characterized by analytical, multinuclear NMR spectroscopic data as well as by single-crystal X-ray diffraction study, which revealed the existence of an agostic C–H⋯Rh interaction in both the species. [Copyright &y& Elsevier]

Reaction of the deprotonated medium-size non-icosahedral carborane 5,6- nido- C 2 B 8 H 12 (1) with Re(CO) 5 Cl affords tricarbonyl anionic complexes of Re [1,1,1-(CO) 3 - isonido- 1,2,4-ReC 2 B 8 H 10 - as PPh 4 - 3a and tmndH- 3b salts (tmnd — N , N , N ′, N ′-tetramethyl-1,8-diaminonaphtaline). Treatment of [tmndH][1,1,1-(CO) 3 - isonido- 1,2,4-MC 2 B 8 H 10 - (M = Mn 2b , Re 3b) with the equivalent amount of CuCl and PPh 3 in CH 2 Cl 2 leads to formation of two isomers of bimetallic complexes [1,3,7(6)-{Cu(PPh 3)}-3,7(6)- μ -H 2 -1,1,1-(CO) 3 - isonido -1,2,4-MC 2 B 8 H 8 (M = Mn 4 , Re 5) with two B-H⋯Cu bonds. All newly obtained compounds were characterized by a combination of analytical and multinuclear NMR spectroscopic data and IR spectroscopy. The structures of complexes 3b and 4 were researched by X-ray diffraction studies. The nature of interaction between {Cu(PPh 3)} and mangana-carborane fragments was clarified based on the computed electron density critical points (within QTAIM framework) and Density Overlap Regions Indicator (DORI) distributions. Transition state between the two diastereomers of 4 was located, the isomerization rate was found to be of order of 1 s−1. Image 1 • Tricarbonyl complexes of rhenium and manganese based on nido- carborane are reported. • Based on X-ray data newly obtained metallacarboranes are of isonido -type of geometry. • Bimetallic {Cu-transition metal} complexes were prepared. • The interaction of Cu(PPh 3) and metallacarborane was studied based on QTAIM and DORI. [ABSTRACT FROM AUTHOR]

Treatment of an anhydrous CoCl 2 with the [Na][C 2 B 8 H 11 ] ( 1 ) generated in situ from the neutral ten-vertex dicarbon carborane [5,6- nido -C 2 B 8 H 12 ] ( 2 ) with NaH in THF at ambient temperature affords the new cobaltacarborane commo cluster closo,nido -[CoH(2,4-C 2 B 8 H 10 )(7,8-C 2 B 8 H 11 )] 1− isolated as its air-stable [Ph 4 P] + ( 3 ) and [Ph 3 PMe] + ( 4 ) salts. As was found from the crystallographically determined structure of 4 and based on the 1 H NMR spectroscopic data for both 3 and 4 , these anionic salts are composed of the Co–H unit that is sandwiched between two {C 2 B 8 } cages; one of these cages, the formally doubly charged [C 2 B 8 H 10 ] 2− ligand, is involved in the η 6 -coordination to the metal center, but another singly charged [7,8-C 2 B 8 H 11 ] 1− ligand, which retains one bridged B–H–B hydrogen atom, is involved through its CB 3 -open face in the η 4 -coordination to the cobalt atom. At room temperature, complexes 3 and 4 exhibited fluxional behavior in solution where the exchange between terminal Co–H and bridging B–H–B hydrogen atoms occurs. This is discussed in detail based on the comparable room- and low-temperature 1 H NMR spectra of 3 . [ABSTRACT FROM AUTHOR]

Abstract: The room-temperature metallation reactions of the K+ salt of the [7,8-(PhCH2)2-7,8-nido-C2B9H10]− anion (1) with the COD-metal μ-chloride dimers [(η4-C8H12)2Rh2(μ-Cl)2] (2) and [(η4-C8H12)2Ir2(μ-Cl)2] (3) in benzene/ethanol solution gave formally 16-electron pseudocloso-type complexes with the η3-cyclooctenyl ligand at the metal vertices, [3-{(1–3-η3)-C8H13}-1,2-(PhCH2)2-pseudocloso-3,1,2-MC2B9H9] [4, M=Rh(III); 5, M=Ir(III)]. No evidence supporting the existence of an agostic C–H⋯M bonding interaction in these compounds was obtained either from the crystallographic or the phase-sensitive 2-D [1H–1H] NOESY/EXSY studies of 4. The extraordinary stability of complexes 4 and 5 can therefore be associated with their cage-deformed cluster structures, where electronically-deficient (16-electron) metal centers are believed to be stabilized by additional electron density released from the polyhedral C–C bond cleavage. DFT solid-state calculations performed for closo (18-electron) and pseudocloso (16-electron) Rh(III) complexes, [3-(η5-C5Me5)-1,2-(PhCH2)2-closo-3,1,2-RhC2B9H9] (6, C–C, 1.7397Å) and [3-{(1–3-η3)-C8H13}-1,2-(4′-MeC6H4)2-pseudocloso-3,1,2-RhC2B9H9] (9, C⋯C, 2.420(2)Å), showed that the electron density transfer from the carborane moiety to the rhodium center is marginally greater for complex 9, in accordance with the idea that electronics rather than sterics play a crucial role in the stabilization of 16-electron pseudocloso-metallacarborane species. [Copyright &y& Elsevier]

The reaction of a new iridium reagent [Ir(η4-1,5-Me2COD)Cl]2 (1) with [nido-7,8-μ-(1′,2′-CH2C6H4CH2&z.sbnd;)-7,8-C2B9H10]−K+ (2) in solution of C6H6–MeOH mixture or in C6H6 afforded either an agostic (C&z.sbnd;H⋯Ir) closo-3-[η3-(endo-1,5-Me2COD)]-1,2-μ-(1′,2′-CH2C6H4CH2&z.sbnd;)-3,1,2-IrC2B9H9 (3) along with closo-3-[η3-(endo-1,5-Me2COD)]-1,2-μ-(1′,2′-CH2C6H4CH2&z.sbnd;)-8-(EtO)-3,1,2-IrC2B9H8 (4) or the only complex 3 in high yield. Complex 3 in dichloromethane solution is quantitatively converted to isomeric η3-exo-allylic complex closo-3-[η3-(1-exo-CH2-5-MeC8H12)]-1,2-μ-[η2-(1′,2′-CH2C6H4CH2&z.sbnd;)]-3,1,2-IrC2B9H9 (5) for a few days. All new complexes 3, 4 and 5 were characterized by single-crystal X-ray diffraction studies, which confirmed the existence of an agostic C&z.sbnd;H⋯Ir interaction in 3 and revealed a weak η2-coordination of the metal atom with one of the aromatic bonds of ortho-xylylene cage substituent in 5. The normal and low-temperature 1H- and 13C/13C{1H}-NMR spectra as well as 2D COSY/HETCOR NMR data obtained for the studied complexes are discussed in details. [Copyright &y& Elsevier]

Reactions of [OsCl2(PPh3)3] 1 with the [NEt4]+ salts of the [6-Ph-nido-6-CB9H11]− anion 2 and the [arachno-6-CB9H14]− anion 3 each proceed selectively in methanol solution with the elimination of one boron-containing fragment from the starting cluster polyhedron, yielding together a short series of three novel 10-vertex hydridoosmamonocarbaboranes of isocloso {OsCB8} cluster geometry. [Copyright &y& Elsevier]

[Display omitted] • The reaction of manganacarborane with triphenylphosphine is described. • Isonido -manganacarborane with triphenylphosphine at the boron atom was isolated. • The position of triphenylphosphine in the carborane ligand was determined by NMR. • The structure of the complex is confirmed by X-ray diffraction analysis. In the reaction of the ionic complex of manganese based on 5,6-dicarba- nido -decaborane [1,1,1-(CO) 3 - isonido -1,2,4-MnC 2 B 8 H 10 - tmdaH± (1) (tmdaH+- protonated form of N , N , N′ , N ′-tetramethyl-1,8-diaminonaphthalene) with triphenylphosphine (PPh 3) in the presence of boron trifluoride etherate (BF 3 ⋅Et 2 O) in benzene, the neutral complex 1,1,1-(CO) 3 –7-PPh 3 - isonido -1,2,4-MnC 2 B 8 H 9 (2) was isolated as one of the main products. The position of the PPh 3 substituent in the carborane ligand was established by 1H, 11B, 31P, 13C, 11B−11B]-COSY, 1H{11B} NMR spectroscopy methods and confirmed by X-ray diffraction analysis. [ABSTRACT FROM AUTHOR]