Influence of the bulkiness of the substituent on the aggregation and magnetic properties of poly(3‐alkylthiophene)s

A series of poly(3‐alkylthiophene)s (P3ATs) ( P1–P5 ) has been synthesized via a Ni(dppp)‐mediated polymerization, varying the bulkiness of the alkyl side chains in order to investigate the influence of the bulkiness of the alkyl substituent on the aggregation and magnetic properties of P3ATs. UV–Vis spectroscopy, performed in solution as well as in film, shows that the stacking of the polymers becomes more complicated as the bulkiness of the side chains increases. Both the π‐interactions and the planarization of the polymer chains are diminished. While aggregation is absent in poor solvent for the polymer with the most bulky side chains, aggregation was present in film, albeit slowed down. This behavior was also confirmed by X‐ray diffraction (XRD) and differential scanning calorimetry (DSC) experiments. Electron spin resonance (ESR) measurements, performed at 300 K on powders, confirmed the trend of decreasing supramolecular order with increasing bulkiness of the side‐chain. Magnetization measurements, performed at 5 and 300 K, are in line with our hypothesis on the influence of π‐interactions and the fraction of planar polymer chains on the coercivity and saturation magnetization, respectively. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014 , 52, 76–86     

Solution of Bohr's collective Hamiltonian for transitional odd-mass nuclei

A numerically feasible method, based on the use of deformed phonons, is developed for the diagonalization of the collective quadrupole Hamiltonian for a system with an odd particle coupled to an anharmonic even core. Examples: the transition from prolate to oblate via γ-unstable shapes and furthermore the $\text{h}{}_{\mathrm{<mtext>9</mtext><mtext>2</mtext>}}$ spectra of the nuclei ¹⁸⁷Ir and ¹⁹⁷Tl.     

The droplet model energy of axially asymmetric nuclei

The shape dependent factors of the droplet model energy are evaluated for the special case of an ellipsoid and expressed in terms of four incomplete elliptic integrals. Generalization to other axially asymmetric shapes is considered.     

Band crossing in the particle-rotor model

The sharpness of the backbending associated with a two-band crossing is shown to be an oscillating function of the degree of shell filling in a particle-rotor model that includes an exact treatment of the two-body recoil term. Both the even-and the odd-nucleon cases are considered. A detailed comparison is made with the cranking model, and also the physical implications of the results are discussed.     

Synthesis,Structure Elucidation,and Pharmacological Evaluation of 5-Methyl-oxymorphone (= 4,5α-epoxy-3,14-dihydroxy-5,17-dimethylmorphinan-6-one)

Synthesis of 5-methyl-oxymorphone ( 3 ) was accomplished by oxidation of 5-methylthebaine ( 4 ) with performic acid, followed by catalytic hydrogenation and cleavage of the 3-MeO group. X-Ray analysis confirmed that the 14-OH group has, like the one in oxymorphone ( 1 ), β-orientation. Pharmacological studies in vivo and in vitro showed 3 to possess slightly less opioid agonistic properties than 1 .     

Eight-membered organosulfur heterocycles. Synthesis of dibenzo[d,g][1,3,6,2]dioxathiaphosphocin and dibenzo[d,g][1,3,6,2]dioxathiasilocin ring systems

The reaction of 2,2′-thiobisphenols with either phenylphosphonous dichloride or phosphorus trichloride followed by an alcohol gave derivatives of the dibenzo[d,g][1,3,6,2]dioxathiaphosphocin ring system. The analogous reaction of 2,2′-thiobisphenols with alkyl and aryl dichlorosilanes gave the heretofore unreported dibenzo[d,g][1,3,6,2]dioxathiasilocin ring system. The analytical and spectral data are reported.