Synthesis of (m-carboran-9-yl)ferrocene and (m-carboran-9-yl)cymantrene

Cross-coupling reactions of 9-iodo-m-carborane with ferrocenylzinc chloride or cymantrenylzinc chloride catalyzed by (Ph₃P)₂PdCl₂ result in the formation of (m-carbo ran-9-yl)ferrocene and (m-carboran-9-yl)cymantrene, respectively. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 3, pp. 542–543, March, 1998.     

Crystal and molecular structures of (9-methylfluoren-9-yl)trimethyltin and (fluoren-9-yl)trimethyltin

Conclusions An increase in the length of the Sn-C (fluorene) bond is not observed in crystals of 9-fluorenyl derivatives of tin, and the variation in the lengths of the Sn-Me bonds is similar to that found in other types of organotin compounds.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 9, pp. 2054–2057, September, 1980.     

Synthesis of Dimethyl (m-Carboran-9-yl)phosphonate and Dimethyl (p-Carboran-2-yl) Phosphonate by Palladium-catalyzed Cross Coupling of 9-I-m- and 2-I-p-Carboranes with Dimethyl Hydrogen Phosphite

Dimethyl (m-carboran-9-yl)- and (p-carboran-2-yl)phosphonates were prepared by (Ph₃)₄Pd-catalyzed cross coupling of 9-I-m- and 2-I-p-carboranes with dimethyl hydrogen phosphite in the presence of triethylamine.     

Synthesis of σ-(o-carboran-9-yl)- and σ-(m-carboran-9-yl)-π-cyclopentadienyldicarbonyliron and their rearrangement in reactions with bromine to π-(o-carboran-9-yl)cyclopentadienyl- and π-(m-carboran-9-yl)cyclopentadienyl-dicarbonylironbromides,respectively

9-o- and 9-m-carboranylcarboxylic acids were used to synthesize σ-(o-carboran-9-yl)- and σ-(m-carboran-9-yl)-π-cyclopentadienyldicarbonyliron. The latter complexes, in reactions with bromine, undergo rearrangement with the cleavage of the BFe σ-bond, involving migration of the 9-o- and 9-m-carboranyl groups into the cyclopentadienyl ring, to give π-(o-carboran-9-yl)cyclopentadienyl- and π-(m-carboran-9-yl)cyclopentadienyl-dicarbonyliron bromides, respectively. A simple method to obtain these acids by the oxidation of 9-alkyl-o- and 9-alkyl-m-carboranes with CrO₃ in CH₃COOH has been found.     

Synthesis,Crystal Structure and Photophysical Property of 4-(9-Oxoacridin-10(9H)-yl) Benzonitrile

A purely organic compound, 4-(9-oxoacridin-10(9 H)-yl) benzonitrile(1), was synthesized and characterized by NMR, UV-Vis, high resolution mass spectrum, and X-ray single-crystal structure analysis. It crystallizes in monoclinic system, space group P21/c with a = 9.7420(2), b = 10.4967(2), c = 14.3896(3) ?, β = 104.755(2)°, V = 1422.94(5), Z = 4, M_r = 296.32, D_c = 1.383 g/cm~3, F(000) = 616, μ = 0.690 mm~(–1), GOOF = 1.035, the final R = 0.0370 and w R = 0.1010 for 2649 observed reflections with I 2σ(I). Compound 1 in tolune exhibits deep blue luminescence with maximum emission peaks at 403 and 419 nm, lifetimes of 3.8 ns and quantum yields of ф = 0.46 at room temperature. The experimental and computational results show that the emission of the compound originates from the acridinone moiety and has π-π* character.     

2D Hydrogen Bonded Copper (II) Coordination Network Constructed by the Combination of Flexible and Rigid Ligands

Complex [Cu(2,2′‐bipy)(H₂L¹)] (ClO₄)₂(1) has been synthesized by the self‐assembly of Cu(ClO₄)₂ with a rigid ligand 2,2′‐bipyridine and a flexible potential tetradentate ligand N, N'‐bis(hydroxyethyl)ethylenediamine (H₂L¹). Crystal analyses reveal that the potentially tetradentate ligand H₂L¹ acts in a tridentate mode by the coordination of one hydroxyl oxygen atom and two amino nitrogen atoms. The Cu(II) atom coordinates additionally with two bipyridyl nitrogen atoms, giving a distorted square pyramidal geometry. Each complex molecule is connected with four surrounding molecules along the ac plane by multiple hydrogen bonds, leading to 2D sheets constituted with 0.7874 nm × 1.0891 nm metallomacrocyclic rectangles. Each vertex of the rectangle is occupied by a copper atom, and the four sides are comprised of multiple hydrogen bonds.     

C60/C70键联1,4-二-(咔唑-9-亚甲基)苯的电化学行为与双光子吸收

设计合成了C60键联1,4-二-(咔唑-9-亚甲基)苯(5)和C70键联1,4-二-(咔唑-9-亚甲基)苯(6), 用红外、核磁共振和MALDI-TOF质谱进行了表征, 确认了化合物5和6的结构, 用循环伏安法研究了化合物5和6的电化学性质, 并用Z扫描对其双光子吸收性质进行了研究.     

Adducts of Cyclodiphosph(V)azenes: Synthesis and Structure

The reaction of Ph₂PCl and PhPCl₂ with bis(trimethylsilyl)sulfur diimide in the presence of GaCl₃ and AlCl₃ yields diadducts of the corresponding cyclodiphosph(V)azene: [Ph₂PN]₂·(GaCl₃)₂ ( 1 ), [Ph₂PN]₂·(AlCl₃)₂ ( 2 ), and [Ph(Cl)PN]₂·(AlCl₃)₂ ( 3 ). This reaction is triggered by Lewis acids, which catalyse the (CH₃)₃Si‐Cl and S₈ elimination. The structures of 1· 2 CH₂Cl₂, 2· 2 CH₂Cl₂ and 3 were determined by single crystal X‐ray studies ( 1 : triclinic, , a = 9.679(2) Å, b = 9.863(2) Å, c = 11.366(2) Å, α = 113.55(3)°; β = 99.59(3)°; γ = 106.67(3)°; V = 902.8(3) ų, Z = 1; 2 : triclinic, , a = 9.639(2) Å, b = 9.804(2) Å, c = 11.321(2) Å, α = 113.71(3)°; β = 99.44(3)°; γ = 106.70(3)°; V = 889.3(3) ų, Z = 1; 3 : orthorhombic, Pbca, a = 14.853(3) Å, b = 9.261(2) Å, c = 16.631(3) Å, V = 2287.7(8) ų, Z = 4.     

Structure of Hydrogen and Hydrophobically Bonded Amphiphilic Copolymer with Poly(methacrylic acid) Complexes as Revealed by Small Angle Neutron Scattering

We study by SANS the structure of intermolecular complexes formed through hydrogen bonding and hydrophobic interactions between poly(methacrylic acid) (PMA) and a neutral copolymer surfactant (PEO-PPO-PEO). The contrast variation method enables us to probe the structure factor of each polymer in the complex and their cross structure factor. The number of copolymer chains, which results from the cooperative action of hydrogen bonding and hydrophobic interactions increases as the charge of the polyacid decreases. The aggregation preserves the micellar core-corona organization of the copolymer and shrinks the polyacid chains which adopt a similar compact structure. Finally, the structure of the aggregates is compared to that of PEO-PMA homopolymer complex observed by SANS.     

Degenerate rearrangement of 9-isopropenyl-9,10-dimethyl-phenanthren-9-yl and 9,10-dimethyl-9-(trans-1-methylprop-1-en-1-yl)phenanthren-9-yl cations

¹H NMR study has shown that long-lived 9-R-9,10-dimethylphenanthren-9-yl cations (R = isopropenyl, trans-1-methylprop-1-en-1-yl) generated in the system HSO₃F-SO₂ClF-CD₂Cl₂ at ?130°C undergo degenerate rearrangement via 1,2-vinyl shifts (ΔG’ = 37 and 39 kJ/mol, respectively, at ?88°C). Analysis of the geometric parameters of the initial structures and transition states calculated by the DFT method indicates that unfavorable steric factors are responsible for the sharp deceleration of 1,2-shifts of the isopropenyl and trans-1-methylprop-1-en-1-yl groups as compared to vinyl and cis-1-methylprop-1-en-1-yl groups, respectively.     

Synthesis and properties of (1,2,3,7,9-pentamethyldipyrrolylmethen-8-yl)-(1,2,3,7,8-pentamethyldipyrrolylmethen-9-yl)methane and bis(1,2,3,7,9-pentamethyldipyrrolylmethen-8-yl)trifluoromethylmethane dihydrobromides

(1,2,3,7,9-pentamethyldipyrrolylmethen-8-yl)(1,2,3,7,8-pentamethyldipyrrolylmethen-9-yl)-methane and bis(1,2,3,7,9-pentamethyldipyrrolylmethen-8-yl)trifluoromethylmethane hydrobromides were synthesized and characterized spectrally (1H NMR, IR, electron absorption spectra). A comparative study was performed of the effect of the bonding site (??- or ??-position of the dipyrrolylmethene) with the methane structural fragment connecting two dipyrrolylmethene chromophores, and trifluoromethyl group on the spectral properties of the molecules of compounds dissolved in organic solvents of different nature and their resistance to thermal oxidative degradation.     

Synthesis,Crystal Structure and Photophysical Property of 2-(9H-carbazol-9-yl)-3-(2-(2,4,5-tri-(9H-carbazol-9-yl)-3,6-dicyanophenoxy)phenoxy) dibenzo[b,e][1,4]dioxine-1,4-dicarbonitrile

A purely organic compound 2-(9 H-carbazol-9-yl)-3-(2-(2,4,5-tri-(9 H-carbazol-9-yl)-3,6-dicyanophenoxy)phenoxy)dibenzo[b,e][1,4]dioxine-1,4-dicarbonitrile, C_(76) H_(40) N_8 O_4, was synthesized and characterized by NMR, UV-Vis, photoluminescenceand X-ray single-crystal structure analysis. The compound crystallizes in monoclinic system, space group P2_1/n with a = 11.6537(3), b = 34.9738(8), c = 15.5053(3) ?, β =101.992(2)°, V = 6181.6(2)?~3, Z = 4, M_r= 1129.18 g/mol, D_c =1.396 g/cm~3, F(000) =2672, μ = 2.239 mm~(–1), GOOF = 1.019, the final R = 0.0577 and wR= 0.1559 for 11925 observed reflections with I 2σ(I). The UV-vis absorption and fluorescence of the compound were discussed. The compound exhibitsyellow-green luminescence with maximum emission peak at 538 nm, and quantum yields of ф = 0.25 and 0.48 in air-equilibrated and degassed toluene at room temperature. Transient decay spectral studies show that compound 1 displays two component decay fashions with a short decay lifetime of 23 ns for the prompt fluoresce anda long decay lifetime of 3.8ms for thermally activated delayed fluorescence. In air-equilibrated toluene, only a short decay lifetime of 17 ns was observed.The experimental and computational results show thatthe emission of the compound originates from the CT excited states.     

Facile Synthesis of Some 3-(Benzimidazol-2-yl)- and 3,6-Di(Benzimidazol-2-yl)-9-ethyl-9H-carbazoles

A simple and efficient synthesis of novel 3-(benzimidazol-2-yl)- and 3,6-di(benzimidazol-2-yl)-9-ethyl-9H-carbazoles is described. The synthetic approach for the preparation of 2-substituted benzimidazoles 4–8 and bis-benzimidazoles 9–12 was achieved by the condensation of carbazole-3-carbaldehyde 2 and carbazole-3,6-dicarbaldehyde 3 with o-phenyldiamines in dimethylformamide or dimethylsulfoxide in moderate to excellent yield. The identities of synthesized compounds were confirmed using ¹H NMR, ¹³C NMR, infrared (IR), and high-resolution mass spectrometry (HRMS).     

First chemoenzymatic synthesis of (R)- and (S)-1-(9H-fluoren-9-yl)ethanol

A simple chemoenzymatic synthesis of 1-(9H-fluoren-9-yl)ethanol stereoisomers is described. The enantiomers were resolved by a kinetically controlled transesterification with vinyl acetate in the presence of commercially available lipases. High-throughput screening and subsequent exhaustive investigation of the utility of the lipases in a stereoselective process of introducing chirality have been carried out. Lipase A from Candida antarctica as a cross-linked aggregate (CAL-A-CLEA) was the most efficient enzyme for the resolution of the title compound providing (S)-1-(9H-fluoren-9-yl)ethanol and its (R)-acetate in enantiopure form (>99% ee). Under mild reaction conditions, excellent enantioselectivity (E = 407), and good isolated yields of the products were obtained.     

Adducts of Niobium (V) and Tantalum (V) Halides. XV. Ligand Exchange of the Adducts with Some Phosphoryl Compounds

The ligand exchange MX₅·L + *L?MX₅·*L + L for the octahedral adducts MX₅·L, in an inert solvent (CH₂Cl₂ or CHCl₃) with neutral ligands, proceeds via a dissociative D mechanism when M = Nb, X = Cl and L = phosphoryl compound. A dissociative interchange I_d mechanism is suggested when M = Nb or Ta, and X = F. A first order rate law and positive values for ΔS* (+4 to +14 cal K^?1 mol^?1) are observed for the exchanges on the pentachloride adducts. However, a second order rate law and large negative values for ΔS* (-15 to -24 cal K^?1 mol^?1) are found for the intermolecular neutral ligand exchange (measured by ¹H-NMR.) and for the intramolecular fluorine exchange (measured by ¹⁹F-NMR.) reactions on the pentafluoride adducts. The fluorine exchange is 2 to 5 times faster than the ligand exchange. The exchanges, on the pentachloride and on the pentafluoride adducts, are slowed down with increasing donor strength of the phosphoryl compound.     

Synthesis,Crystal Structure and Fungicidal Activity of 3,4-Dichloro-5-(6-chloro-9-(4-fluorobenzyl)-9H-purin-8-yl)isothiazole

3,4-Dichloro-5-(6-chloro-9-(4-fluorobenzyl)-9H-purin-8-yl)isothiazole,a novel purine derivative,was synthesized by the cyclization of pyrimidine amine.Its struc...     

Vanadium Hydrogen Sulfate (I): Chemoselective Trimethylsilylation of Alcohols and Deprotection of Trimethylsilyl Ethers

Trimethylsilylation of alcohols with hexamethyldisilazane (HMDS) catalyzed by V(HSO₄)₃ under mild and completely heterogeneous reaction condition is reported. The method is highly chemoselective for the protection of alcohols in the presence of phenols, amines and thiols. Also, the deprotection of trimethylsilyl ethers is performed in the presence of V(HSO₄)₃ at room temperature in good to high yields.