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Normal modes and their dispersion have been obtained for polychloroprene in the trans form using Wilson's G F matrix method as modified by Higg's for an infinite polymeric chain. Urey Bradley force field has been used. Several new assignments, which are missing in earlier work, are reported. The assignments of lower frequency modes have been confirmed using inelastic neutron scattering data. The characteristic features of dispersion curves have been explained. Variation of heat capacity as a function of temperature has been predicted. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011

Polyaniline is unique among conducting polymers in that its electrical properties can be reversibly controlled both by the oxidation state of the main chain and by protonation. In the present communication we report normal modes and their dispersion in polyaniline pernigraniline base (PANI PNB) form using Urey - Bradely force field which in addition to valence force field accounts for the non-bonded interactions in the gem and cis configurations and tension terms. Some of the distinguished features of the dispersion curves such as cross-over and Von Hove type of singularities are discussed and possible explanations are given in terms of symmetry considerations. Several new assignments, which are missing in earlier work, are reported.

The normal modes and their dispersions for poly(L-tryptophan) (PLTR) in the α-helical form have been obtained in a reduced zone scheme with Wilson's GF matrix method as modified by Higgs. Dynamic studies of the α form are of special significance as it is the predominant secondary structure for protein molecules. X-ray and circular dichroism (CD) studies by Peggion et al. have confirmed the α-helical conformation of PLTR. The side group of PLTR is more complicated than that of other natural polypeptides. It consists of both a pyrrole and a benzene ring along with a CH2 group. Optically active frequencies corresponding to the zone center and zone boundary are identified and discussed. Some of the characteristic features of the dispersion curves are repulsion accompanied by an exchange of character and von Hove singularities. The heat capacity has been calculated via densities of state with Debye's equation in the temperature range of 220–390 K and has been compared with experimental measurements. © 2003 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 42: 316–332, 2004

Poly(S-benzyl-L-cysteine) (PBLC) is a S-benzyl derivative of the natural amino acid poly(L-cysteine). Its normal modes and their dispersion in antiparallel β-sheet conformation have been obtained within the first Brillouin zone using Wilson's G.F. matrix method, as modified by Higgs for an infinite polymeric chain. The zone center frequencies and the Urey Bradley force field have been obtained by best fitting the observed Fourier transform IR (FTIR) absorption bands. The characteristic features of dispersion curves such as crossing, repulsion, and exchange of character are discussed. Predictive values of heat capacity in the temperature range of 50-500 K are reported.

SYNOPSIS Poly(P-benzyl-L-aspartate) (PBLA) is an unusual polypeptide, which is capable of going into four different conformations, namely, left-handed a helix, right-handed a helix, o helix, and fi pleated sheet. The present work is a complete study of normal modes and their dispersion in the unusual left-handed a form. A special feature of some of the dispersion curves is their tendency to bunch in the neighborhood of helix angle. This is attributed to the presence of strong intramolecular interactions. Crossing and repulsion between the dispersion curves is also observed. The N-deuterated analogue of PBLA has been studied to check the validity of assignments and force field (Urey Bradley). Specific heat has been obtained from dispersion curves via density of states. A comparative study of left-handed and right-handed forms is presented. 0 1996 John Wiley & Sons, Inc.

Amido/imido alcohol/2-phenyl-3-hydroxyethylquinazolin-4 (3H) -one 1 on treatment with benzoic acid in the presence of conc. H2SO4 yields m-(aralkylamido/imidoalkyl/2-phenyl-3-ethyl-3H-4-oxoquinazolinyl) benzoic acids 2. The acid chloride of 2 on reaction with hydrazine hydrate affords m-(aralkylamido/imidoalkyl/2-phenyl-3-ethyl-3H-4-oxoquinazolinyl) benzoic acid hydrazides 4 which on condensation with an aromatic aldehyde in acetic acid gives m(aralkylamido/imidoalkyl/2-phenyl-3-ethyl-3H-4-oxo-quinazolinyl) benzoic acid hydrazones 5. Compounds 5 undergo cyclization with phenoxy acetic acid in the presence of thionyl chloride in dry benzene to furnish 1-[m(aralkylamido/imidoalkyl/2-phenyl-3-ethyl-3H-4-oxo-quinazolinyl-benzamido)]-3-phenoxy-4-phenyl-2-azetidinones 6. The antiviral and antifungal activities of 6 have been reported. IPC: Int.Cl. 7 C 07 C 59/54 // A 61 P 31/12

N-methylaminoalkoxides of titanium of the type Ti(OR)4−n(O · CHR′ · CH2 · NR″R‴)n where R = Et and Pr1; n = 1–4; and R′ = R″ = H, R‴ = Me; R′ = H, R″ = R‴ = Me; R′ = R″ = R‴ = Me, synthesized by the reactions of titanium alkoxides with aminoalcohols, show interesting variations in their properties like physical state, volatility and molecular complexity. I.r. and p.m.r. spectra of these derivatives have been recorded. A few interchange reactions with methanol and tert-butanol have also been carried out. These aminoalkoxides get cleaved with acetyl chloride and undergo insertion reactions with phenylisocyanate, thus providing the first examples of insertion reactions in such derivatives. Umsetzungen von Titanalkoxiden mit N-Methylaminoalkoholen N-Methylaminoalkoxide des Titans vom Typ Ti(OR)4−n(O · CHR′ · CH2 · NR″R‴)n, die durch Umsetzungen von Titanalkoxiden mit Aminoalkoholen dargestellt wurden, zeigten interessante Unterschiede in ihren Eigenschaften. IR- und PMR-Spektren wurden registriert sowie Austauschreaktionen mit Methanol und t-Butanol durchgefuhrt. Diese Aminoalkoxide werden mit Acetylchlorid gespalten und gehen Einschubreaktionen mit Phenylisocyanat ein, was ein erstes Beispiel fur Einschubreaktionen bei solchen Verbindungen darstellt.

Hermans' orientation factor can be evaluated only when the diatropic and paratropic interferences arise from planes which form an orthogonal set. This is only approximately satisfied in case of both cellulose I and cellulose II. In the present communication an exact expression has been derived which can be evaluated from x-ray measurements, angle between face normals of paratropic interferences, and the optical constants.

A normal coordinate analysis for cyclic tetra-L-alanine molecule is reported. A comparison of amide modes and other low-frequency vibrations sensitive to conformational changes is made with those in poly-L-alanine. Intramolecular coupling coefficients are calculated using perturbation treatment.

A statistical thermodynamic approach based on the application of the Ising model for ferromagnetism is outlined to explain the phase transition in isolated single-stranded helical macromolecules. The transition is characterized by the degree of helicity and the lengths of uninterrupted helical and random-coil regions. The theoretical predictions for the temperature dependence of helicity in case of poly-l-lysine and poly(l-glutamic acid) are compared with the experimental results of Applequist and Doty and Doty, Yang, and others. The application of the theory to the crystalline–amorphous transition in polyethylene and polypropylene is also suggested and some preliminary results are reported. Une approche thermodynamique statistique basee sur l'application du modele de Ising pour le ferromagnetisme est soulignee pour expliquer la transition de phases dans des macromolecules isolees et helicoidales. La transition est caracte risee par le degre d'helicite et par la longueur des regions helicoidales et empelotonnees ininterrompues. Les predictions theoriques en ce qui concerne la dependance thermique de l'helicite dans le cadre de la poly-l-lysine et de l'acide poly-l-glutamique sont comparees avec des resultats experimentaux de Applequist, Doty et Doty, Yang et autres. L'application de la theorie a la transition cristallin–amorphe dans le cas du polyethylene et du polypropylene a ete egalement suggeree et certains resultats preliminaires sont rapportes. Ein statistisch-thermodynamischer, auf der Anwendung des Ising-Modells fur den Ferromagnetismus beruhender Erklarungsversuch der Phasenumwandlung in isolierten, einstrahnigen helixformigen Makromolekulen wird beschrieben. Die Umwandlung wird durch den Grad an Helixcharakter und die Lange der ununterbrochenen Helix- und Knauelbereiche gekennzeichnet. Die theoretischen Voraussagen fur die Temperaturabhangigkeit des Helixcharakters im Falle von Poly-l-lysin und Poly-l-glutaminsaure werden mit den Versuchsergebnissen von Applequist und Doty sowie Doty, Yang und anderen verglichen. Eine Anwendung der Theorie auf die kristallin–amorphe Umwandlung in Polyathylen und Polypropylen wird ebenfalls vorgeschlagen und einige vorlaufige Ergebnisse werden mitgeteilt.

O-Trialkylgermaniumamidoximes are prepared by reaction between trialkylgermanium chloride and amidoxime in the presence of triethylamine. These new derivatives are characterised by elemental analysis, molecular weight measurement and infrared spectroscopy.

N-methylaminoalkoxides of titanium of the type Ti(OR)4−n(O · CHR′ · CH2 · NR″R‴)n where R = Et and Pr1; n = 1–4; and R′ = R″ = H, R‴ = Me; R′ = H, R″ = R‴ = Me; R′ = R″ = R‴ = Me, synthesized by the reactions of titanium alkoxides with aminoalcohols, show interesting variations in their properties like physical state, volatility and molecular complexity. I.r. and p.m.r. spectra of these derivatives have been recorded. A few interchange reactions with methanol and tert-butanol have also been carried out. These aminoalkoxides get cleaved with acetyl chloride and undergo insertion reactions with phenylisocyanate, thus providing the first examples of insertion reactions in such derivatives. Umsetzungen von Titanalkoxiden mit N-Methylaminoalkoholen N-Methylaminoalkoxide des Titans vom Typ Ti(OR)4−n(O · CHR′ · CH2 · NR″R‴)n, die durch Umsetzungen von Titanalkoxiden mit Aminoalkoholen dargestellt wurden, zeigten interessante Unterschiede in ihren Eigenschaften. IR- und PMR-Spektren wurden registriert sowie Austauschreaktionen mit Methanol und t-Butanol durchgefuhrt. Diese Aminoalkoxide werden mit Acetylchlorid gespalten und gehen Einschubreaktionen mit Phenylisocyanat ein, was ein erstes Beispiel fur Einschubreaktionen bei solchen Verbindungen darstellt.

2-(Tributylstannoxy)-, 2(triphenylstannoxy)- and 2-(trimethylsiloxy)-3- hydro-4-alkyl- or -4-phenyl-1,3,5,2-oxadiazaboroles have been synthesized, and their properties examined.

A variety of new 3-aryl-4-phenyl-1,3,5,2-oxadiazaboroles of the type (where X = OR, Ph, OSiMe3, OSnBu3, OSnPh3 and and Ar = N-phenyl or N-m-tolyl) have been synthesized by different reaction routes. The products have been characterized by elemental analyses and physicochemical measurements such as IR, PMR and molecular weights.

Bis(1,3,5,2-oxadiazaborol-2-yloxy)tetrabutyldistannoxanes have been synthesized by the reaction of amidoxime, boric acid and dibutyltin oxide. A probable structure for the dimeric species has been proposed on the basis of molecular weight and IR spectral data.

Fluoro-β-diketone derivatives of titanium of the general formula (OR) 4-n Ti [OC(CF 3 ) = CHCOR'] n (R = Et and Pr 1 ; R' = CF 3 . Ph and C 4 H 3 S and n = 1 or 2), have been synthesized by the reaction of titanium alkoxides with fluoro-β-diketones. A few interchange reactions with tertiary butyl or amyl alcohols have also been studied.

N-Methylaminoalkoxides of zirconium of the type, Zr(OPri)4-n(O.CHR′.CH2.NR″R′)n, where R′ = R′ = H, R′ = Me; R′ = H, R′ = R′ = Me; R′ = R′ = R′ = Me; and n = 1–4, have been synthesized by the reactions of zirconium isopropoxide with aminoalcohols. These are characterized by elemental analyses and IR spectra. Insertion reactions of zirconium aminoalkoxides have been studied for the first time and have been shown to yield interesting derivatives with Zr-N bonds.