Preparation, structure and coordination properties of 3,3-bis(diisopropylamino)-3-thioxo-1-(2,4,6-tri-tert-butylphenyl)-1,3- diphosphapropene

(Z)-1-Chloro-2-(2,4,6-tri-tert-butylphenyl)-2-phosphaethenyllithium was allowed to react with bis(diisopropylamino)-phosphenium triflate to afford the corresponding 1,3-diphosphapropene which was converted to 3-thioxo-1,3-diphosphapropene [(Z)-Mes*P = C(Cl)-P(= S)(NiPr2)2]. The coordination properties of 3-thioxo-1,3'-diphosphapropene were investigated with carbonyltungsten(0) and dichloroplatinum(II) reagents, and the molecular structure of the chelate dichloroplatinum(II) complex was unambiguously determined by X-ray crystallography together with the free ligand. The dichloroplatinum(II) complex underwent intramolecular cyclisation involving C-H activation to give a 5,7-di-tert-butyl-3,3-dimethyl-l-(phosphinomethyl)-1-phosphaindane derivative as well.     

Preparation of 2,4-bis(2,4,6-tri-tert-butylphenyl)-1,3-diphosphacyclobutenes from 2-(2,4,6-tri-tert-butylphenyl)-1-phosphaethyne and alkyllithiums

2-(2,4,6-Tri-tert-butylphenyl)-1-phosphaethyne was allowed to react with 0.5 eq. of alkyllithium to afford 2,4-bis(2,4,6-tri-tert-butylphenyl)-1,3-diphosphacyclobutenes through an intramolecular cyclisation of a 1,3-diphosphabuta-1,3-diene intermediate.     

2-(2,4,6-tri-tert-butylphenyl)-1-phosphaethin, 1,4-bis-(trimethylsiloxy)-1,4-bis-(2,4,6-tri-tert-butylphenyl)-2, 3-diphosphabutadien

The title compounds are prepared for the first time by reaction of 2,4,6-tri-tert-butyl-benzoylchloride and tris-(trimethylsilyl)-phosphane.     

Reactions of 1,2-di(2-thienyl)-3,4-bis[(2,4,6-tri-t-butylphenyl)phosphinidene]cyclobutene

Reactions of a sterically protected 1,2-di(2-thienyl)-3,4-bis[(2,4,6-tri-t-butylphenyl)phosphinidene]cyclobutene were investigated. The diphosphinidenecyclobutene reacted with elemental sulfur or transition metal reagents to form a thiaphosphirane derivative or the corresponding transition metal complexes, respectively. Reactions of the di(2-thienyl)diphosphinidenecyclobutene with butyllithium followed by treatment with electrophiles afforded functionalized di(2-thienyl)diphosphinidenecyclobutene derivatives.     

Preparation of sterically protected 3,4-bis[(2,4,6-tri-tert-butylphenyl)phosphinidene]cyclobutene derivatives having ring-fused structures

[reaction: see text] Sterically protected 3,4-diphosphinidenecyclobutenes, having ring-fused structures, were prepared. Structures of 8,9-bis[(2,4,6-tri-tert-butylphenyl)phosphinidene]bicyclo[5.2.0]non-1(7)-ene and its dichloropalladium(II) complex were analyzed by X-ray crystallography. A geometrical change induced by the complex formation was exhibited by X-ray crystallographic analysis. The geometrical change in solution was also suggested by (1)H NMR spectroscopy in CDCl(3).     

Aggregation-induced and crystallization-enhanced emissions of 1,2-diphenyl-3,4-bis(diphenylmethylene)-1-cyclobutene

1,2-Diphenyl-3,4-bis(diphenylmethylene)-1-cyclobutene can be induced to emit efficiently by aggregate formation, with the crystalline aggregates emitting brighter, bluer lights than their amorphous counterparts.     

Preparations and properties of polymers containing 3,4-bis[(2,4,6-tri-t-butylphenyl)phosphinidene]-1,2-di(2-thienyl)cyclobutene moieties

Reaction of 1,8-bis[5-{(2,4,6-tri-t-butylphenyl)phosphinoethynyl}-2-thienyl]octane with butyllithium followed by treatment with 1,2-dibromoethane afforded a new polymer containing 3,4-bis[(2,4,6-tri-t-butylphenyl)phosphinidene]-1,2-di(2-thienyl)cyclobutene units. The polymer was allowed to react with bis(benzonitrile)dichloropalladium to give the polymer complex. A Sonogashira coupling reaction between ethynyltrimethylsilane and 4-bromonitrobenzene proceeded in DMF at 100 °C to give 4-nitro(trimethylsilylethynyl)benzene in the presence of the polymer complex, CuI, and triethylamine.     

Synthesis of 1,2-bis[2-methyl-5(3,4-difluorophenyl)-3-thienyl] perfluorocyclopentene

2-Methylthiophene (1) was treated at 0°C with liquid bromine to form 3,5-dibromo-2-methylthiophene (2) which reacted with tributyl borate to give 2-methyl-3-bromo-5-boronate thiophene (3) at −78°C. Treatment of 3 with 3,4-difluorobrombenzene gave 2-methyl-3-bromo-5-(3,4-difluorophenyl)thiophene (4). Finally, a novel photochromic dithienylethene compound, 1,2-bis [2-methyl-5(3,4-difluorophenyl)-3-thienyl]perfluorocyclopentene (DT-1), was synthesized by the reaction of 4 with perfluorocyclopentene at −78°C. The compound (DT-1) was characterized by IR, NMR, MS, elemental analysis and its photochromic behavior was also discussed. __________ Translated from Chinese Journal of Organic Chemistry, 2007, 27(10): 1282–1284 [译自: 有机化学]     

Cyano-substituted polyamides and polyimides prepared from 2,6-bis(3-aminobenzylidene)-1-dicyanomethylene-cyclohexane

Cyclohexanone was condensed with 3-nitrobenzaldehyde in the presence of dry HCl as catalyst to afford 2,6-bis(3-nitrobenzylidene)cyclohexane. The condensation of the latter with malononitrile yielded 2,6-bis(3-nitrobenzylidene)-l-dicyanomethylene-cyclohexane that was hydrogenated to the corresponding diamine. The latter was used as a reagent for preparing various unsaturated polyamides and polyimides bearing dicyanomethylene segments. In addition, a model diamide and diimide were synthesized. The polymers were soluble in polar aprotic solvents and certain strong inorganic and organic acids. They were crosslinked upon heating at 300°C for 20 hr. The crosslinked polymers were stable up to 377–408°C in N₂ or air and afforded anaerobic char yields of 65–70° at 800°C.     

Phospha-s-triazines. IV. Degradation studies of 1-diarylphospha-3,5-bis(perfluoroaliphatic)-2,4,6-triazines and 1,3,-bis(diarylphospha)-5-perfluoroaliphatic-2,4,6-triazines

Thermal and thermal oxidative stability evaluations were performed on mono- and diphospha-s-triazines at 235 and 316°C using sealed Pyrex ampoules. The specific compounds studied were: 1-diphenylphospa-3,5-bis(perfluoro-n-heptyl)-2,4,6-triazine, 1-diphenylphospha-3,5-bis(perfluoro-alkylether)-2,4,6-triazines, their respective pentafluorophenyl analogues, 1,3-bis(diphenylphospha)-5-perfluoro-n-heptyl-2,4,6-triazine and 1,3-bis(diphenylphospha)-5-perfluoroalkylether-2,4,6-triazine. All the compounds wherein phenyl groups were present on the phosphorous exhibited good thermal stability up to 316°C; the analogous pentafluorophenyl substituted materials were degraded extensively at these temperatures. The oxidative stability of both the mono- and diphospha-s-triazines was excellent at 235°C, but at 316°C some degradation was observed. This was more pronounced in compounds containing the perfluoroalkyl moiety on carbon than in the perfluoroalkylether substituted members of the series.     

Structural evolution and magnetic properties of Co(II) coordination polymers varied from 1D to 3D constructed by 1,4-bis(1,2,4-triazol-1-ylmethyl)benzene

Seven Co(II) coordination polymers, [Co(btx)(3)(H(2)O)(2)](ClO(4))(2)·(btx)·2H(2)O (1), [Co(btx)(3)(H(2)O)(2)](BF(4))(2)·(btx)·2H(2)O (2), [Co(btx)(2)(H(2)O)(2)](NO(3))(2)·2H(2)O (3), [Co(btx)(2)Cl(2)] (4), [Co(btx)(BA)(2)(H(2)O)(2)]·2HBA (5), [Co(btx)(IPA)] (6) and [Co(3)(btx)(3)(BTA)(2)(H(2)O)(2)] (7) (btx = (1,4-bis(1,2,4-triazol-1-ylmethyl)benzene), HBA = benzoic acid, H(2)IPA = isophthalic acid, H(3)BTA = benzene-1,3,5-tricarboxylic acid), have been hydrothermally synthesized and characterized. 1 and 2 are isostructural and show a 1D Co-μ(2)-btx-Co chain structure, in which btx acts as both a bridging and terminal ligand. 3 is also a 1D chain structure but different from 1 and 2. The Co(II) ions are bridged by double μ(2)-btx to form Co(2)-btx(2) rings, which were further connected into 1D chains by sharing the Co(II) ions of the rings. 4 exists as a 2D grid with (4,4) topology structure. When aromatic acid was introduced to the synthetic system, three other coordination polymers 5-7 were obtained. In 5, the 1D chain is as that of 1, except that the terminal ligand was replaced by BA(-). 6 shows a two-fold parallel interpenetration framework featuring a 6-c uninodal net with (3(3),4(6),5(5),6) Schlafli topological symbol. 7 is an interesting 3D framework, which contains a 2-nodal net motif with the unprecedented (3(6),4(2),5(6),6)(3(9),4(9),5(3))(2) topology structure. The influence of the varieties of the structures and magnetic properties are studied and discussed in detail.