Titanium-Catalyzed Polymerization of a Lewis Base-Stabilized Phosphinoborane.

The reaction of the Lewis base-stabilized phosphinoborane monomer tBuHPBH2 NMe3 (2 a) with catalytic amounts of bis(η5 :η1 -adamantylidenepentafulvene)titanium (1) provides a convenient new route to the polyphosphinoborane [tBuPH-BH2 ]n (3 a). This method offers access to high molar mass materials under mild conditions and with short reaction times (20 °C, 1 h in toluene). It represents an unprecedented example of a transition metal-mediated polymerization of a Lewis base-stabilized Group 13/15 compound. Preliminary studies of the substrate scope and a potential mechanism are reported.

Molecular structures of a series of substituted bis(η5-cyclopentadienyl)titanium dihalides CpR2TiX2 [X = F, Cl, Br and I; R = CHPh2, CH(p-Tol)2 and adamantyl].

Metallocene dihalides and derivatives thereof are of great interest as precursors for catalysts in polymerization reactions, as antitumor agents and, due to their increased stability, as suitable starting materials in salt metathesis reactions and the generation of metallocene fragments. We report the synthesis and structural characterization of a series of eleven substituted bis(η5-cyclopentadienyl)titanium dihalides, namely bis[η5-1-(diphenylmethyl)cyclopentadienyl]difluoridotitanium(IV), [Ti(C18H15)2F2], bis{η5-1-[bis(4-methylphenyl)methyl]cyclopentadienyl}difluoridotitanium(IV), [Ti(C20H19)2F2], and bis{η5-1-[bis(adamantan-2-yl)methyl]cyclopentadienyl}difluoridotitanium(IV), [Ti(C15H19)2F2], together with the bromide and iodide analogues, and the chloride analogues of the diphenylmethyl and adamantyl complexes. These eleven complexes were prepared by the reaction of the corresponding bis(η5:η1-pentafulvene)titanium complexes with different hydrogen halides (Cl, Br and I). The titanocene fluorides become available via chloride-fluoride exchange reactions.

Epiphysiolysis of the femoral neck due to closed reduction of an adolescent hip dislocation with a 4-year follow-up: a case report and review of the literature.

This case study discusses a 13-year-old girl diagnosed with a displaced Salter Harris II fracture of the proximal femoral epiphysis post reduction of a dislocated hip. Radiographs before reduction revealed a small fracture of the inferomedial femoral head. This, however, did not induce concern before reduction. The patient underwent reparative surgery of the epiphysis only to develop a collapsed femoral head, which was remedied through total hip arthroplasty. A decrease in blood flow, the delicacy in reduction, and unknown predispositions might have been contributing factors toward the unique development in this case.