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Treatment of a recently reported complex [Ph4P][closo,nido-CoH(2,4-C2B8H10)(7,8-C2B8H11)] (1) either by H2O2 in acetone or NaH in THF leads to the loss of both the bridging and terminal hydrides yielding the diamagnetic salt of an anionic commo-cobaltacarborane [Ph4P][Co(2,4-isonido-C2B8H10)2] (2) with the {CoC2B8}-cluster units adopting a distorted skeletal geometry of the isonido-type. The anionic commo complex 2 reacts with in situ generated cationic [CuPPh3]+ species to give stable copper–cobalt zwitterion [Ph3PCu][Co(2,4-isonido-C2B8H10)2] (3) with four two-electron, three-center (B–H)4···Cu bonds, and exhibits no fluxional behavior in solution. Complex 3, at the same time, in CH2Cl2 in the presence of 2-fold excess of PPh3 readily converts to a new anionic species [(Ph3P)3Cu][Co(2,4-isonido-C2B8H10)2] (4) which retains initial isonido geometry. All newly obtained diamagnetic commo complexes were characterized by a combination of analytical and multinuclear NMR spectroscopic data and by single-crysta...

The anionic manganese tricarbonyl complex [1,1,1-(CO)3-isonido-1,2,4-MnC2B8H10]–was synthesized in the form of PPN and tmdaH salts (PPN is bis(triphenylphosphine)iminium, tmda is N,N,N’,N’-tetramethyl-1,8-diaminonaphthalene) by the reaction of the deprotonated form of the medium-size non-icosahedral carborane 5,6-nido-C2B8H12 with Mn(CO)5Br. The structure of the complex [tmdaH][1,1,1-(CO)3-isonido-1,2,4-MnC2B8H10] was deter-mined by X-ray diffraction.

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 .

The reaction of the middle-cage carborane 5,6-nido-C2B8H12 with the dimeric rhodium complexes [(η2-C8H14)2RhCl]2 or [(η4-C8H12)RhCl]2 in a MeOH/C6H6 mixture gave the anionic commo-rhodacarborane [PPN][commo-1,1′-Rh(isonido-2,4-C2B8H10)2] (as a mixture of meso and dd/ll isomers) and its 7-B-methoxylated derivative [PPN][commo-1,1′-Rh(7-MeO-isonido-2,4-C2B8H9)(isonido-2,4-C2B8H10)] in moderate yields. The latter was subjected to the thermal isonido-to-closo rearrangement to form the new commo-cluster [PPN][commo-1,1′-Rh(closo-2,3-C2B8H9OMe)(closo-2,3-C2B8H10)]. The newly synthesized compounds were characterized by NMR spectroscopy and X-ray diffraction.

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.

A reaction of anhydrous CuCl2 with Na salts of the medium-cage carborane [7-X-nido-5,6-C2B8H10]−(X = H or I) derivatives in THF leads to new cupracarborane commo-clusters, [commo-9,9′-Cu(nido-7,8-C2B8H11)2]− and [commo-9,9′-Cu(11-I-nido-7,8-C2B8H10)2]−, in moderate yields. The clusters were isolated as stable [Ph3PEt]+ salts and characterized by 1H, 31P{1H}, and 11B/11B{1H} NMR spectroscopy and X-ray crystallography (for the unsubstituted derivative). The use in this reaction of the reducing agent Na2SO3 considerably increases the yields of both complexes from 25 and 18% to 74 and 68%, respectively.

Zwitterionic 4,8,8′-exo-{Ph3PCu}-4,8,8′-(μ-H)3-commo-3,3′-Co(1,2-C2B9H9)-(1′,2′-C2B9H10) and ionic [(PPh3)3Cu][commo-3,3′-Co(1,2-C2B9H11)2 complexes were synthesized in moderate yields by the reaction of anionic commo-complex [Cs][commo-3,3′-Co-(1,2-C2B9H11)2]) in a CH2Cl2 solution with anhydrous CuCl2 or CuCl in the presence of PPh3. The complexes were also synthesized by alternative methods and characterized by NMR and X-ray diffraction methods.

AIM analysis of electron density distribution based on B3LYP calculations, carried out for nido-5,6-C2B8H12 and its anion [nido-C2B8H11]−, and the data of IR spectroscopy lead to conclusion that the formally 6-member face is of greater size due to incorporation of adjacent triangular face and two extra-hydrogen atoms. In nido-5,6-C2B8H12 open face is characterized by complete absence of electron density. The Laplacian of electron density is used to predict the sites of electrophilic attack, which position was shown to depend on a number of extra-hydrogen atoms. The predictions are in agreement with known experimental data.

The vibrational spectrum, geometrical structure and electron-density distribution (EDD) of the formally closo (2n+2)-electron cluster species [B11H11]2– have been studied. The presence of two low-frequency vibrational modes is evidence of cluster nonrigidity. A rationale for this lies in the results of EDD calculations which show that the polyhedron lacks two-centre edge-localized B–B bonds of the 6k–5k type and that its surface exhibits two six-membered rings with low electron density. Thus, the polyhedron does not consist of deltahedral faces only and therefore does not have a genuine closo structure. The data obtained also allow further elucidation of the “diamond-square-diamond” mechanism as commonly applied to the fluxionality of [B11H11]2– in solution.(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)

The presence of low-frequency large-amplitude modes in the vibrational spectrum, experimental and computed data on interboron distances and the results of the topological analysis of the electron density distribution in 2,3-C 2 B 9 H 11 , the molecule of a neutral 11-vertex dicarbaborane, lead to the conclusion that this polyhedron is not a deltahedron. This species lacks at least four two-center B–B bonds and thus it is formed not by triangular faces only. Hence, this dicarbaborane, as well as monocarbaborate [2-CB 10 H 11 ] − , another representative of 11-vertex polyhedra, do not have the closo -structure, traditionally ascribed to both by formal [2 n +2]-electron count.

The monocarbon carborane [Cs][nido-7-CB(10)H(13)] reacts with the 16-electron [RuCl(2)(PPh(3))(3)] in a solution of benzene/methanol in the presence of N,N,N',N'-tetramethylnaphthalene-1,8-diamine as the base to give a series of 12-vertex monocarbon arene-biruthenacarborane complexes of two types: [closo-2-[7,11-exo-RuClPPh(3)(mu,eta(6)-C(6)H(5)PPh(2))]-7,11-(mu-H)(2)-2,1-RuCB(10)H(8)R] (5, R = H; 6, R = 6-MeO; 7, R = 3-MeO) and [closo-2-(eta(6)-C(6)H(6))-10,11,12-[exo-RuCl(PPh(3))(2)]-10,11,12-(mu-H)(3)-2,1-RuCB(10)H(7)R(1)] (8a, R(1) = 6-MeO; 8b, R(1) = 3-MeO, inseparable mixture of isomers) along with trace amounts of 10-vertex mononuclear hypercloso/isocloso-type complexes [2,2-(PPh(3))(2)-2-H-3,9-(MeO)(2)-2,1-RuCB(8)H(7)] (9) and [2,5-(Ph(3)P)-2-Cl-2-H-3,9-(MeO)(2)-2,1-RuCB(8)H(6)] (10). Binuclear ruthenacarborane clusters of both series were characterized by a combination of analytical and multinuclear NMR spectroscopic data and by single-crystal X-ray diffraction studies of three selected complexes, 6-8. In solution, isomers 8a,b have been shown to undergo the isomerization process through the scrambling of the exo-[RuCl(PPh(3))(2)] fragment about two adjacent triangular cage boron faces B(7)B(11)B(12) and B(8)B(9)B(12).

The presence of two low-frequency large-amplitude modes in the vibrational spectrum, experimental and computed data on B–B interatomic distances and the results of a topological analysis of the electron density distribution in the molecule of an 11-vertex monocarbaborate [2-CB10H11]− lead to the conclusion that this polyhedron is not rigid, missing at least four double-center B–B bonds and thus being formed not only by triangular faces. Hence, this carbaborane does not have the closo-structure traditionally ascribed to it on formal [2n+2]-electron count grounds.

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.

Heating of 1,1,3-(PPh3)3-1-H-1,2,4-RuC2B8H9 with 2-(hydroxymethyl)bicyclo[2.2.1]hepta-2,5-diene in arene solvents (benzene, toluene, or mesitylene) unexpectedly afforded the ruthenium arene complexes 1-(η6-arene)-3-(C7H9CH2O)-isonido-1,2,4-RuC2B8H9 containing the nortricyclene fragment in the carborane ligand.

A series of arene-ruthenium 11-vertex complexes 3-Cl-1-(η6-arene)-isonido-1,2,4-RuC2B8H9 (4a-4h) and 6-Cl-1-(η6-arene)-isonido-1,2,4-RuC2B8H9 (5a, 5b, 5f, 5g) (arene = p-xylene (a), mesitylene (b), p-cymene (c), benzene (d), toluene (e), hexamethylbenzene (f), 1,2,4,5-tetramethylbenzene (g), 1,2,4-trimethylbenzene (h)) have been obtained as isomeric mixtures 4a, 4b, 4f, 4g and 5a, 5b, 5f, 5g or, predominantly, as single isomers 4c-4e, 4h by the treatment of nido-5,6-C2B8H12 (1) with [RuCl2(PPh3)3] (2), either in the corresponding arene solvents at 80-85 °C (in the case of 4a-4e and 5a, 5b) or in the arene/1,2-dichloroethane solution under reflux (in the case of 4f-4h and 5f, 5g) in the presence of N,N,N',N'-tetramethylnaphthalene-1,8-diamine. The compounds prepared were characterized by combination of analytical, IR and multinuclear NMR data, including a crystallographic study of 4b. A possible pathway for the formation of isomeric complexes 4 and 5 is discussed.

RuCl2(PPh3)3 (1), when heated with an equimolar amount of nido-5,6-C2B8H12 (2) in toluene for a few hours, effected rather unexpected polyhedral contraction of 2 to give the new half-sandwich small ruthenacarborane closo-C2B4H6Ru(PPh3)2HCl (3) in moderate yield along with minor amounts of the two isomeric 11-vertex ruthenacarboranes [3-Cl-1-(η6-C6H5Me)-1,2,4-RuC2B8H9] (4) and [6-Cl-1-(η6-C6H5Me)-1,2,4-RuC2B8H9] (5) with open MC2B8 cluster structure. These new complexes were characterized by 1H, 13C, and 11B NMR spectroscopy and, in the case of 3 and 5, also by an X-ray crystal structure analysis.

It has been shown by IR and NMR spectroscopy that cyclic trimeric perfluoro-o-phenylenemercury (o-C6F4-Hg)3 (1) is capable of binding closo-[B10H10]2- and closo-[B12H12]2- anions to form complexes [[(o-C6F4Hg)3](B10-H10)]2- (2), [[(o-C6F4Hg)3]2(B10H10)]2-(3), [[(o-C6F4Hg)3](B12H12)]2- (4), and [[(o-C6F4Hg)3]2(B12H12)]2- (5). According to IR data, the bonding of the [B10H10]2- and [B12H12]2- ions to the macrocycle in these complexes is accomplished through the formation of B-H-Hg bridges. Complexes 2, 3, and 5 have been isolated in analytically pure form and have been characterized by spectroscopic means. X-ray diffraction studies of 3 and 5 have revealed that these compounds have unusual sandwich structures, in which the polyhedral di-anion is located between the planes of two molecules of 1 and is bonded to each of them through two types of B-H-Hg bridges. One type is the simultaneous coordination of a B-H group to all three Hg atoms of the macrocycle. The other type is the coordination of a B-H group to a single Hg atom of the cycle. According to X-ray diffraction data, complex 2 has an analogous but half-sandwich structure. The obtained complexes 2-5 are quite stable; their stability constants in THF/acetone (1:1) at 20 degrees C have been determined as 1.0 x 10(2)Lmol(-1), 2.6 x 10(3)L(2)mol(2), 0.7 x 10(2)Lmol(-1), and 0.98 x 10(3)L(2)mol(-2), respectively.

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.

The first η2-olefinic monocarbon metallacarbone closo-2-(Ph3P)-1-N,2-[μ-(η2-CH2CHCh2)]-1-N-(σ-CH2CHCH2)-2,1- RhCB10H10 has been prepared by the reaction of the dimeric anion {[Ph3PRhB10H10CNH2]2-μ-H}−[PPN]+ with allyl bromide and characterized by a combination of spectroscopic methods and a single-crystal X-ray diffraction study. The variable temperature 1H and 13C NMR studies revealed the fluxional behavior of the η2-olefinic complex in CD2Cl2 solution which is associated with the allyl side-chain exchange process.

A novel 12-vertex monocarbon hydridorhodacarborane closo -2,2-(Ph 3 P) 2 -2- H -1-(Me 3 N)-2,1-RhCB 10 H 10 1 has been synthesized by the reaction of Rh(PPh 3 ) 3 Cl ( 2 ) with nido -B 10 H 12 CNMe 3 ( 3 ) under alkaline conditions. At low temperature 1 exists as a mixture of two preferred conformers in solution, both having C S symmetry, in accord with the hindered rotation of the (Ph 3 P) 2 RhH vertex with respect to the CB 4 face of the monocarbon carborane cage. Complex 1 readily reacts with chlorine-containing reagents to form mononuclear 16-electron closo -2-(Ph 3 P)-2-Cl-1-(Me 3 N)-2,1-RhCB 10 H 10 ( 5 ), whose structure was unambiguously confirmed by an X-ray diffraction study. The results of an X-ray diffraction study of the closely related dicarbon carborane derivative closo -3,3-(Ph 3 P) 2 -3-Cl-3,1,2-RhC 2 B 9 H 11 ( 10 ), prepared from closo -3,3-(Ph 3 P) 2 -3- H -3,1,2-RhC 2 B 9 H 11 by analogy with 5 , are also reported.

Doxycycline (2), a tetracycline antibiotic extensively used in chemotherapy, was obtained stereoselectively from the hydrogenation of methacycline (1), catalysed by novel rhodium-carborane complexes.

The vibrational spectrum, geometrical structure and electron-density distribution (EDD) of the formally closo (2n+2)-electron cluster species [B11H11]2– have been studied. The presence of two low-frequency vibrational modes is evidence of cluster nonrigidity. A rationale for this lies in the results of EDD calculations which show that the polyhedron lacks two-centre edge-localized B–B bonds of the 6k–5k type and that its surface exhibits two six-membered rings with low electron density. Thus, the polyhedron does not consist of deltahedral faces only and therefore does not have a genuine closo structure. The data obtained also allow further elucidation of the “diamond-square-diamond” mechanism as commonly applied to the fluxionality of [B11H11]2– in solution.(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)

Treatment of [nido-B10H12CH]-Cs+ with RuCl2(PPh3)3 in methanol under gentle reflux afforded the two novel 10-vertex monocarbon ruthenacarboranes 2-Cl-2,5-(Ph3P)2-2-H-3,9-(MeO)2-2,1-RuCB8H6 (3) and 2,2-(Ph3P)2-2-H-3,9-(MeO)2-2,1-RuCB8H7 (4) along with a small amount of the 8-vertex complex (PPh3)2HRuCB6H4(OMe)3 (6). The 10-vertex clusters 3 and 4 on the basis of their capped-tricapped-trigonal-prismatic geometry, established for 3 by a single-crystal X-ray diffraction study, and the formal Wadian electron-counting arguments can be regarded as hyper-closo species having n rather than n + 1 skeletal electron pairs.

It has been shown by IR and NMR spectroscopy that cyclic trimeric perfluoro-o-phenylenemercury (o-C6F4-Hg)3 (1) is capable of binding closo-[B10H10]2- and closo-[B12H12]2- anions to form complexes [[(o-C6F4Hg)3](B10-H10)]2- (2), [[(o-C6F4Hg)3]2(B10H10)]2-(3), [[(o-C6F4Hg)3](B12H12)]2- (4), and [[(o-C6F4Hg)3]2(B12H12)]2- (5). According to IR data, the bonding of the [B10H10]2- and [B12H12]2- ions to the macrocycle in these complexes is accomplished through the formation of B-H-Hg bridges. Complexes 2, 3, and 5 have been isolated in analytically pure form and have been characterized by spectroscopic means. X-ray diffraction studies of 3 and 5 have revealed that these compounds have unusual sandwich structures, in which the polyhedral di-anion is located between the planes of two molecules of 1 and is bonded to each of them through two types of B-H-Hg bridges. One type is the simultaneous coordination of a B-H group to all three Hg atoms of the macrocycle. The other type is the coordination of a B-H group to a single Hg atom of the cycle. According to X-ray diffraction data, complex 2 has an analogous but half-sandwich structure. The obtained complexes 2-5 are quite stable; their stability constants in THF/acetone (1:1) at 20 degrees C have been determined as 1.0 x 10(2)Lmol(-1), 2.6 x 10(3)L(2)mol(2), 0.7 x 10(2)Lmol(-1), and 0.98 x 10(3)L(2)mol(-2), respectively.

Racemiccloso-rhodacarboranes,vis. closo-(η3,2-C7H3-2-CR 2 1 )-1-R2-2-R3-3,1,2-RhC2B9H9 (R1=R2=R3=H; R1=H, R2=R3=Me; R1=R2=R3=Me) and (closo-2,2-(η3,2-C7H7-2-CH2)-2,1,7-RhC2B9H11), were successfully separated into enantiomers by high-performance liquid chromatography (HPLC).

A convenient, highly efficient, and environmentally safe procedure for the preparation of trimethylarsine was proposed. A quantitative yield of this compound in the reaction of As2O3 with AIMe3 was attained for the first time by using mechanochemical activation of the process.

1. The o- and m-carboranes undergo electrophilic polymercuration by mercury fluoroacetate in trifluoroacetic acid at the boron atoms to give the pentamercury-substituted o-carboranes and trimercury-substituted m-carboranes. 2. The electrophilic monomercuration of o-carborane proceeds in the 9(12) and 8(10) positions of the o-carborane nucleus, while the electrophilic mono- and dimercuration of m-carborane proceed predominantly in the 9 and 10 position of the m-carborane nucleus.

1. In the presence of AlCl3, CH3Br, CH3I, and C2H5Br alkylate o- and m-carborane at the boron atoms in the carborane ring, with the formation of B-alkyl-o- and B-alkyl-m-carboranes, consisting of from one to eight alkyl groups per molecule. 2. In the presence of AlCl3, the reaction of i-C3H7Br with o- and m-carborane leads chiefly to the formation of the corresponding B-mono-, diisopropyl-o-, and diisopropyl-mcarboranes. 3. In the presence of AlCl3, arsacarborane and phosphocarborane react with C2H5Br. Alkylation at the boron atoms of the carborane ring takes place. 4. In the presence of AlCl2, cyclopentadienyldicarbolylcobalt reacts with CH3I, C2H5Br, and i-C3H7Br, undergoing alkylation as well as halogenation at the boron atoms of the carbonate ring.

1. The synthesis of 4-substituted derivatives of naphtho[1, 2]-o-carborane by the cyclization of derivatives of 1-phenyl-o-carborane has been carried out. 2. A simple synthesis of benzocarborane from vinyl-o-carboranylacetic acid has been proposed.

A simple method is reported for the synthesis of 9,9-bis(m-carboranyl) from 9,9′-bis (m-carboranyl) mercury upon its decomposition under the influence of catalytic amounts of (PPh3)3RhCl in HMPA. Under these conditions, 9-m-carboranylmercury chloride easily forms 9-chloro-m-carborana and metallic mercury. A simple method for symmetrization of 9-o- and 9-m-carooranylmercury chloride into 9,9′-bis(o- and m-carboranyl)mercury under influence of sodium stannite in an alkaline medium was elaborated.

1. Samples of 9-o- and 9-m-carboranylsulfenyl chlorides, aryl (9-m-carboranyl) sulfides, phenyl(9-m-carboranyl)sulfoxide, and phenyl(9-m-carboranyl) sulfone were prepared for the first time. 2. Similar to alkylsulfinic acids, 9-m-carboranylsulfinic acid readily disproportionates to give 9-m-carboranylthiolsulfonate and 9-m-carboranylsulfonic acid. 3. 9-m-Carboranylthiol adds to compounds with an activated double bond in the presence of base.

The stable carbenium cations in the zwitterionic complexes closo-3,3,3-(CO)3- 3,1,2-ReC2B9 H 10-1- C +RR′ (R = R′ = H; R = H, R′ = Me; R = R′ = Me) have been prepared by protonation of closo-3,3,3-(CO)3-3,1,2-ReC2B9H10-1-CH2OR (R = H, Me) and closo-3,3,3-(CO)3-3,l,2-ReC2B9H10-1-CRCH2 (R=H, Me). Some of the reactions of the zwitterions with neutral and charged nucleophilic reagents have been studied. The crystal and molecular structure of closo-3,3,3-(CO)3-3,1,2-ReC2B9 H 10- 1- C + Me2 has been established. It is shown that the carbocationic centre in these zwitterions is stabilized by direct ReC interaction.

1. A simple method has been developed for the synthesis of bis(9-o-carboranyl) ditelluride and bis(9-m-carboranyl) ditelluride by means of the electrophilic telluration of o-and m-carborane by TeCl4 in the presence of AlCl3.

1. A method was proposed for the preparation of 9-acetyl-o- and 9-acetyl-m-carborane by treating bis(9-o-carboranyl)mercury and bis(9-m-carboranyl)mercury with AcCl in the presence of AlCl3. 2. A method was proposed for the symmetrization of 9-chloromercuri-o- and 9-chloromercuri-m-carborane to bis(o-carboranyl)mercury and bis(m-carboranyl)mercury by treatment with LiAlH4 in ether. 3. In the Beckmann rearrangement of 9-acetyl-m-carborane oxime the B-C bond is cleaved, and the 9-m-carboranyl group migrates to the nitrogen atom.

1. The complexes of Pd(acac)2 and Pd(OAc)2 with triphenylphosphine catalyze the telomerization of isoprene with water in the presence of CO2, which leads to the formation of isomeric dimethyloctadienols. 2. The complexes of Pd(acac)2 and Pd(OAc)2 with tricresyl phosphite catalyze the formation of the isomeric dimethyloctadienol acetates from isoprene and CH3COOH. 3. In acetone the complexes of Pd(acac)2, Pd(OAc)2 with triphenylphosphine smoothly and almost completely dimerize isoprene to 2,7-dimethyl-1,3,7-octatriene.

1. Thermal decomposition of bis-(9-o- and 9-m-carboranyl)mercury containing B-Hgσ bonds occurs with the formation of metallic mercury and a carboranyl radical. In the main the latter disproportionate giving carborane and oligocarborane and recombine to an insignificant extent into B,B'-biscarboranyl. 2. Thermal decomposition of 9-o and 9-m-carboranylmercury chlorides containing B-Hg σ-bonds occurs homolytically with the formation of metallic mercury and 9-chloro-o- and m-carboranes respectively. 3. A simple method has been proposed for making symmetrical the 9-o-, 9-m-, and 2-p-carboranylmercury chlorides (or trifluoroacetates) into the corresponding biscarboranylmercury derivatives under the action of an alkaline solution of sodium stannite.

1. A simple method was proposed for obtaining the bis(9-o- and 9-m-carboranyl) disulfides from the o- and m-carboranes and S2C12 in the presence of A1C13, and also a simple method for reducing the latter to the 9-o- and 9-m-carboranylthiols. 2. When the o- and m-carboranes are reacted with SC12 in the presence of A1C13 the main products are the bis (o- and m-carboranyl) disulfides.

Various 9-sulfur-containing compounds of the o- and m-carboranes were obtained from the 9-mercapto-substituted o- and m-carboranes.