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The acid dissociation constant (pKa) of inorganic oxoacids was calculated using density functional theory (DFT) with the hybrid cluster-continuum approach. The results showed that calculated pKa va...

A wide variety of aldehydes are efficiently dimerized to esters by a catalytic amount of (C5Me5)2LnCH(SiMe3)2 (Ln = Nd, La). The reaction is applicable to the synthesis of polyesters from dialdehydes. A stoichiometric reaction of the lanthanum complex with benzaldehyde indicates the intermediacy of alkoxo complexes in the catalysis.

Germanium-germanium bonds of digermanes, octamethyltrigermane, and decamethyltetragermane add readily to alkynes in the presence of Pd(dba)2–2P(OCH2)3CEt (dba = dibenzylideneacetone).

Partial insertion of functionalized acetylenes RC≡CH (R = 4-Me2NC6H4, 4-pyridyl, Me3SiOCH2) into Si-Si bonds of a poly[p-(disilanylene)phenylene] (1) and poly(methylpropylsilylene) smoothly proceeded by Pd(dba)2-2P(OCH2)3CEt (dba = dibenzylideneacetone) catalyst. A modified polymer of 1 with a (4-dimethylaminophenyl)vinylene group showed higher conductivity than 1 when doped with iodine.

High molecular weight poly(methylsilylene) is obtained in a good yield through dehydrogenative condensation of methylsilane catalyzed by (C5Me5)2NdCH(SiMe3)2. At a high temperature, polymerization process involves cross-linking via the loss of methane. Pyrolysis of the resulting polymer gives β-SiC in a high yield. Blend with a carbon-rich polymer like poly(phenylsilylene) is effective to prevent the formation of contaminative metallic silicon during ceramization.

Poly[{(E)-1,1,2,2-tetramethyldigermanylene}ethenylene], poly[(1,1,2,2-tetramethyldigermanylene)-2,5-thienylene], poly[(1,2-dimethyl-1,2-diphenyldigermanylene)-p-phenylene], and poly(methylphenylgermylene) were synthesized. SbF5 doping of above polymers showed the conductivities of the order of 10−4 S/cm, which were similar to, or a little higher than, those of corresponding silicon analogues.

Dehydrogenative condensation of trihydrosilanes is catalyzed by (C5Me5)2NdCH(SiMe3)2 to give polysilanes in high yields. In the polymerization of PhSiH3, molecular weight of the polymer becomes higher with an increase of the reaction temperature. Cyclic structures are indicated for oligomers larger than pentamers by FD-MS spectroscopy.

Organic halides (RX) underwent dehalogenative germylation and germylene insertion type reactions with ClMe2GeGeMe2Cl in the presence of Pd(PPh3)4 as catalyst to give RGeMe2Cl and RGeMe2X respectively.

Dehydrogenation of cycloalkanes to cycloalkenes is catalyzed by RhCl(CH2=CH2) (PMe3)2 under ethylene pressure at a high temperature over 170 °C. Ethylene insertion into sp3 C–H bond of cycloalkanes...

The Pd(dba)2–2P(OCH2)3CEt (dba = dibenzylideneacetone) system exhibited highly efficient catalysis in the insertion of acetylenes into Si–Si bonds of hexamethyldisilane, octamethyltrisilane, poly[(disilanylene)phenylene] , poly[(disilanylene)ethylene], and poly(dimethylsilylene).

Halomethylsilanes (MeSiCl3, Me3SiI, Me2SiCl2, Me3SiCl, and Me3SiBr) undergo oxidative addition to IrH(pipr3)2 in situ generated from IrH5(pipr3)2 and two equivalent neohexene to form halo(organosilyl)iridium(III) complexes. In addition, the resulting (methylsilyl)iridium complexes undergo β-hydride elimination reactions leading to the formation of dihydroiridium species.

The Si-Si bond in XSiMe2SiMe2Y (X, Y = F, F; Cl, Cl; Cl, Me; Br, Me) was readily cleaved with Pt(PEt3)3 to give cis-(XMe2Si)(YMe2Si)Pt(PEt3)2 complexes. On the other hand, ISiMe2SiMe3 selectively underwent oxidative addition at the Si–I bond to result in the formation of trans-(Me3SiMe2Si)PtI(PEt3)2.

Active methylene compounds undergo reductive alkylation with aldehydes when heated at 135–230 °C under synthesis gas of 100 atm in the presence of ruthenium carbonyl.

High conversions are achieved in photo-assisted dehydrogenation of alkane catalyzed by RhCl(CO)(PMe3)2 using bulky hydrocarbons like 2,2,5,5-tetramethylhexane and 1,3,5-tri-t-butylbenzene as inert solvents. Main by-product in cyclooctane dehydrogenation at a high conversion is 1,3-cyclooctadiene.

Diffusion coefficients (D) of arsenite and arsenate at various pH, or degrees of dissociation, were reported by diffusion cell, some values of which are newly reported in this letter. Systematic de...

When wrapped with amylose, oligo(p-phenylenevinylene) exists in a state that is isolated from the external environment, thereby hampering the π–π interactions and displaying an intense blue emissio...

Linear oligosilanes form inclusion complexes with schizophyllan to induce a preferential helical conformation within the chiral environment constructed by wrapping with schizophyllan.

Poly[2,7-(9-oxo-9-phosphafluorenylene)-alt-co-(1,4-arylene)]s, readily prepared from 2,7-dibromo-9-oxo-9-phosphafluorenes and arylene bisboronates, behaved as extended π-conjugated polymers in the ...

Poly(phenazasiline)s (PPhenaz) and related phenazasiline copolymers having arylenediethyndiyl units in the backbone (PPhE) were prepared by organometallic processes. PPhenaz films show reversible electrochromic behavior upon electrochemical treatment. A double layer electroluminescent device comprising PPhenaz with n-C8H17 groups bound to the silicon displays high performance similar to those comprising a typical hole-transport material, poly(N-vinylcarbazole).

Palladium complexes efficiently catalyze the addition of O,O,S-triphenyl phosphorothioate to terminal alkynes to produce (Z)-1-(diphenoxyphosphinyl)-2-(phenylthio)alkenes in high yields with high regio- and stereoselectivity.

Dehydrogenative coupling reactions of bis(hydrosilyl)benzenes with [Ru3(CO)12] afford moderate yields of the polymers [-SiRR′-Ru(CO)4-Ru(CO)4-SiRR′-C6H4-]n which exhibit large solvent-dependent change of the UV-VIS spectra. The absorption maximum of the polymer is markedly red-shifted, compared with monomeric complex [PhMe2SiRu(CO)4Ru(CO)4SiMe2Ph].

Hydrosilylation polymerization between octakis(hydridosilsesquioxane) and diynes gives thermally stable polymers which are soluble in usual organic solvents.

Diphenylphosphinic acid adds across the triple bond of terminal alkynes in the presence of Ru3(CO)12, leading to regioselective formation of alkenyl diphenylphosphinates CH2=C(R)[OP(O)Ph2].

Pt(cod)2 catalyzed dehydrocoupling of acyclic and cyclic secondary silanes R1R2SiH2[R1, R2 = alkyl group; R1 + R2 = (CH2)n(n = 3,4,5); R1 + R2 = o-biphenylene] to afford polysilanes while a (CH3)2Pt(cod)-catalyzed reaction of silacyclobutane (n = 3) resulted in selective ring-opening polymerization.

[1]Silaferrocenophanes (1) underwent dimerization reaction in the presence of palladium-trialkylphosphine complexes. A mechanistically-related [2]platinasilaferrocenophane complex was formed when 1 was treated with Pt(PEt3)3.

A platinum complex-catalyzed dehydrogenative double silylation reaction of 1,2,4,5-tetrakis(dimethylsilyl)benzene with cyclic diynes gave ladder polymers quantitatively.

lodotrimethylsilane reacted with styrene derivatives in the presence of triethylamine and a palladium catalyst to give β-styrylsilanes.

Alkanes are catalytically dehydrogenated to alkenes with RhCl(CH2=CH2)(PMe3)2 (λmax 416 nm) under visible light irradiation in the presence of ethylene. The reaction proceeds smoothly even at room temperature; the quantum yield of cyclooctane dehydrogenation was 0. 10 at 25 °C.

Organic halides such as PhI, ArBr, and β-bromostyrene reacted with di- or monochlorovinylsilanes or triethoxyvinylsilane in the presence of triethylamine and palladium catalysts to give β-substituted vinylsilanes in excellent to moderate yields.

Aldehydes are effectively reduced to corresponding alcohols at room temperature using alkane as a hydrogen donor by the catalysis of RhCl(CO)(PMe3)2 under irradiation. Chemoselective reduction of aldehyde in the presence of ketone is achieved.

Meta-substituted benzaldehydes were obtained as the major product in the carbonylation of mono-substituted benzenes via the C–H activation catalyzed by RhCl(CO)(PMe3)2 under irradiation.

Asymmetric synthesis of alcohols has been achieved via hydrogenation of silyl enol ethers catalyzed by rhodium complexes with a variety of optically active phosphine ligands.

RhCl(CO)(PR3)2-catalyzed and photoassisted carbonylation of decane leading to the formation of C11 aldehydes and/or 1-nonene was remarkably affected by the wavelength; irradiation with λ > 295 nm was essential to the formation of 1-nonene and undecanal. By cutting off λ > 325 nm, 1-nonene formation was completely suppressed, and a series of isomeric C11 aldehydes were obtained.

A high turnover number was achieved in the photo-assisted carbonylation of C–H bonds of benzene catalyzed by RhCl(CO)(PMe3)2 under mild conditions (1 atm, 37 °C) to give mainly benzaldehyde. Cyclohexane could also be carbonylated under the same conditions.

Vaska-type complexes such as MCl(CO)L2 (M = Rh or Ir, L = tertiary phosphine) or the Wilkinson complex RhCl(PPh3)3 underwent halogen exchange reactions with halosilanes Me3SiX (X = Br, I) to give MX(CO)L2 or RhX(PPh3)3 respectively with the formation of Me3SiCl. The reaction of RhH(CO)(PPh3)3 with MeSiCl3 also afforded RhCl(CO)(PPh3)2.

The reaction of benzene with methyl acrylate and ethylene catalyzed by RhCl(CO)(PMe3)2 under irradiation gave methyl cinnamate and styrene, respectively. The reaction of toluene afforded meta-substituted isomers as major products.

Pentane and decane were regioselectively transformed into 1-butene and 1-nonene with the simultaneous formation of acetaldehyde by photocatalysis in the presence of RhCl (CO)(PMe3)2 under carbon monoxide.

Direct silylation of arenes with triethylsilane or hexamethyldisilane were catalyzed by RhCl(CO)(PMe3)2 under irradiation.

Reductive elimination of cis-bis(phenyldimethylsilyl)bis(phosphine)platinum(II) complexes was found to occur to give sym-diphenyltetramethyldisilane together with redistribution by-products. Addition of free phosphine was favorable for the reductive elimination, and the disilane was formed in more than 80% yields.

The reaction of phenylacetylene, tolane, or isoprene with cis-bis(dimethylphenylsilyl)bis(methyldiphenylphosphine)platinum readily took place to result in 1,2- or 1,4- double silylation, respectively. Ethylene also underwent double silylation with the platinum complex, but styrene selectively gave E-2-(dimethylphenylsilyl)styrene.

HRu(CO)4− could be in situ generated from Ru3(CO)12 in the presence of basic salts in amide solvents when exposed to syn gas. In the reduction of carbon monoxide, HRu(CO)4− generating catalyst systems selectively gave methanol. HRu(CO)4− exerted higher reactivities in the reduction of acetaldehyde and in the bimolecular reductive elimination with CH3COCo(CO)3PPh3, as compared to HRu3(CO)11−.

Dienes were formed by the dehydrogenative coupling of olefins via the photocatalyzed C–H activation in the presence of RhCl(CO)(PMe3)2 at an ambient temperature.

Mixed Langmuir–Blodgett (LB) films of (10-butyl-9-anthryl)-3-propanoic acid (1) and arachidic acid were prepared and their UV-Vis spectra were measured. Photodimerization of 1 in these LB films was successfully performed with monochromatic light.

Styrene, α-ethylstyrene and phenyl vinyl ether are hydroformylated asymmetrically in the presence of chlorocarbonylbis(diphenylneomenthylphosphine)rhodium (I) as catalyst.

Olefins and dihydrogen were catalytically formed from alkanes at an ambient temperature in the presence of RhCl (CO)(PMe3)2 under irradiation.

High optical yields up to ca. 77% were obtained in the hydrogenation of 2-phenyl-1-butene by use of a rhodium catalyst complexed with an insoluble phosphinite derived from 6-O-triphenylmethylcellulose. Recycling of the catalyst was also investigated.

C–H bond activation of benzene and pentane in the presence of isocyanides was promoted by RhCl(CO) (PR3)2 to result in the isocyanides insertion into C–H bonds.

Disodium tetracarbonylferrate reacts with 1,3-dibromopropane in the presence of phosphine to give a 2-ferracyclopentanone complex, (Remark: Graphics omitted.)