Synthetic and Structural Studies of Ethyl Zinc β-Amidoenoates and β-Ketoiminates

A set of heteroleptic ethyl zinc β-amidoenoates (1, 2) and β-ketoiminates (3) of the form [LZnEt]2 with varying steric bulk have been synthesised via the reaction of diethylzinc with β-aminoenoate ligands HL1 and HL2 and β-ketoimine HL3. These complexes have been characterised via 1H and 13C NMR, mass spectrometry and single-crystal X-ray diffraction, which unambiguously determined all three structures as dimeric species in the solid state. We observe the unusual dimerisation of 1 and 2 through coordination of the central zinc atom to the methine carbon of the second monomer, which gives these complexes high reactivity. The thermal properties of complex 3 are explored via thermal gravimetric analysis (TGA), to investigate their potential as single-source precursors to zinc oxide, which shows that 3 has a significantly lower decomposition temperature as compared to its bis-ligated counterpart [Zn(L3)2], which gives 3 promise as a single-source precursor to zinc oxide.

Synthesis of Trimeric Organozinc Compounds and their Subsequent Reaction with Oxygen

A conventional solution‐based route to a cyclic trimeric organozinc compound [{Zn(Et)(β‐diketonate)}₃] (β‐diketonate=OC(OMe)CHC(Me)O, 1) is described, with 1 structurally characterized for the first time. The ligand selection of bidentate β‐diketonates is shown to be key to isolating a cyclic trimer. Additional reaction of β‐diketonates with diethyl zinc were spectroscopically characterized as compounds of the type [{Zn(Et)(β‐diketonate)}_n] (β‐diketonate=OC(Me)CHC(Me)O, 2, OC(OtBu)CHC(Me)O, 3). Further studies have shown that selective oxidation of these species produces cubanes of the general formula [{Zn(OC(R)CHC(Me)O)₂Zn(Et)OEt}₂] (R=OMe, 4; Me, 5; OtBu, 6), allowing a high oxygen content whilst remaining structurally suitable for use as precursors. The successful deposition of thin films of zinc oxide through aerosol‐assisted chemical vapor deposition (AACVD), using a novel precursor, is described and fully characterized.

Digital foot deformities in the arthritic patient

Relieving pain and preventing deformity in the rheumatoid foot are best accomplished early in the disease course. Although the treatment of digital deformities may not differ significantly in the rheumatoid versus the nonrheumatoid patient, early and more aggressive management is most important in the rheumatoid patient. The digital deformities associated with inflammatory arthritis are progressive as long as the disease is active. Therefore, it becomes necessary to treat these patients both medically and mechanically to slow the progression of the digital deformities. In determining whether medical, surgical, or biomechanical treatment options are appropriate, the physician must examine multiple considerations. These include disease activity, presence or absence of symptoms, degree of deformity and resultant potential for complications, shoe intolerance, and level of activity. Changing attitudes have dictated that little benefit is gained from withholding treatment until the disease is so-called burnt out. It is in the patient's best interest to maintain function whenever possible to allow for increased productivity. The psychosocial ramifications of this approach are obvious.

Nonmetallic foreign bodies in the foot: radiography versus xeroradiography

Nonmetallic foreign bodies were embedded in cadaver feet. Standard x-rays and xerograms were taken and compared. The results appear to indicate that standard x-rays remain the more clinically practical means of screening for foreign bodies. The literature regarding xeroradiography suggests that this is superior to radiography in detection of nonmetallic foreign bodies. By embedding nonmetallic foreign bodies in cadaver feet and comparing standard x-rays to xerograms, the examiner should be able to confirm or disprove this premise.