Reactivity of electrophilic micro-phosphinidene complexes with heterocumulenes: formation of the first sigma-pi-aminophosphaimine complexes [Mn2(CO)8{micro-eta1,eta2-P(NiPr2)=NR}] and diazoalkane insertions into metal-phosphorus bonds

The bridging phosphinidene complexes [Mn2(CO)8(micro-PNiPr2)] and [Co2(CO)4(micro-dppm)(micro-PNR2)](NR2=NiPr2, TMP) react with heterocumulenes RN3, CH2N2 and Ph2C=N=N to form complexes with micro-eta1,eta2-aminophosphaimine, micro-eta1,eta2-aminophosphaalkene and micro-eta1,eta2-aminophosphadiphenylmethylazaimine ligands, respectively.     

Bilateral Mixed Laryngoceles: Simultaneous Strobovideolaryngoscopy and External Video Examination

A music medicine practice affords a unique opportunity to diagnose and treat laryngeal music performers. Strobovideolaryngoscopic (SVL) and external video examination of the voice professional or brass instrument player may focus on the vocal folds, yet abnormalities of the supraglottis, neck, and thorax should be appreciated and documented. Laryngoceles are uncommon laryngeal disorders but may occur in up to 5% of benign laryngeal lesions. While many laryngoceles are asymptomatic, they may cause a cough, hoarseness, stridor, sore throat, pain, snoring, or globus sensation. In particular, musicians who play brass instruments are at high risk for laryngocele development. We highlight two patients with symptomatic laryngoceles to present anatomical, historical, classification, epidemiological, diagnostic, and management considerations.     

Fluorinated aminoalkoxide and ketoiminate indium complexes as MOCVD precursors for In2O3 thin film deposition

The syntheses of two distinctive types of indium complex derived from trimethylindium (InMe(3)) are reported. The first kind has a generalized structural formula [InMe(2)(amak)](2), where (amak)H is an abbreviation for a series of chelating amino alcohol ligands HOC(CF(3))(2)CH(2)NHR, R = (CH(2))(2)OMe (1), Me (2), and Bu(t) (3), as well as HOC(CF(3))(2)CH(2)NMe(2) (4); while the second type of complex is illustrated by [InMe(2)(keim)] (5), for which (keim)H is a tridentate ketoimine ligand of structural formula O=C(CF(3))CH(2)C(CF(3))=NCH(2)CH(2)NMe(2). The solid-state structures of 2 and 5 were determined using single crystal X-ray diffraction studies. For the aminoalkoxide complexes 2-4, the existence of dimeric In(2)O(2) core structures in the solid state has been established with the amino fragment located trans to the alkoxide ligands, in a molecular arrangement which is in contrast to the distorted, trigonal bipyramidal geometry observed for the ketoiminate complex 5. Moreover, VT NMR studies of 2 revealed a rapid dimer-to-monomer equilibration and simultaneous rupture of the N-->In dative interaction, affording two interconvertible isomers related by having the N-Me substituents in either trans or cis dispositions. For complexes 2 and 5, deposition of In(2)O(3) thin films was successfully conducted at temperatures 400-500 degrees C, using O(2) as the carrier gas to induce indium oxide deposition and to suppress carbon impurity present in the thin film. Scanning electron micrographs (SEMs) revealed the surface morphologies. The atomic composition of these films was examined by both X-ray photoelectron spectroscopy (XPS) and Rutherford backscattering (RBS) methods, while X-ray diffraction studies (XRD) confirmed the formation of a preferred orientation along the (222) planes.     

APPLICATION OF SHELLAC IN POLYMERS

Abstract

Lac is the only known natural resin of animal origin. It is the secretion of a tiny insect known as Kerriar lacca (formally called Laceifer lacca). The lac-forming tiny insect grows on some types of trees, mostly abundant in tropical countries, including India. The secretion of the lac insect hardens in air and forms a covering on the body of the insect. This covering or the nest forms a continuous incrustation on the branches of the host trees. Lac is collected by scraping the incrustation from the branches of the trees.     

A synergistic organoiron flame-retarding/smoke-suppressing system for ABS

Commercial acrylonitrile butadiene styrene (ABS) polymers are among the most flammable of the currently available range of thermoplastic materials. In addition to having a rather low limiting oxygen index (LOI) value in the range 18.3–18.8, ABS polymers also produce compious amounts of smoke and hazardous gases when burnign in the air. In a recent study directed towards preparing and evaluating compounds which would simultaneously reduce the flammability and smoke produced from burning thermoplastic polymers, a synergistic flame-retarding/smoke-suppressing system based on organoiron compounds has been produced, which when properly compounded into ABS/PVC [poly(vinyl chloride)] blends more than doubles the LOI nad at the same time reduces smoke production significantly.