Tokiko Uchida

Novel organic SHG materials

Abstract Of 140 newly synthesized chalcone-analogous materials, 56 specimens were observed to be efficient for nonlinear optical second harmonic generation (SHG). The SHG efficiency of 3-(4-chlorophenyl)-1-(3-pyridyl)-2-propen-1-one is discussed on the basis of crystal structure and MO calculation. In this crystal, molecules arrange themselves almost ideal manner for SHG.

Hydrogen rearrangements in CsHSeO4 accompanied with both the phase transition and domain-boundary-movement

Hydrogen rearrangements accompanied with the movement of domain boundaries in CsHSeO 4 below the ferroelastic phase transition temperature ( T c =128°C) and possible motional states of hydrogens above T c were studied based on the crystal structure obtained in the X-ray re-examination at room temperature and twinning conditions for ferroelastic domains observed below T c . The crystal was confirmed to be monoclinic with the space group P 2 1 / c and to have a superlattice structure below T c , while it is tetragonal with the space group I 4 1 / amd above T c . It was deduced by taking account of symmetry change from P 2 1 / c to I 4 1 / amd and twinning conditions that the hydrogen bonds in CsHSeO 4 above T c are broken instantaneously and the hydrogens are hopping among the 16-fold (f) equivalent positions, leading to so called three-dimensional superionic conductivity of hydrogens above T c .

Structural study of chalcone derivatives

Abstract Crystal structures of several SHG-active chalcone derivatives were determined by X-ray analysis. The phase-matching direction of a 1-(3-thienyl)-3-(4-chlorophenyl)-2-propen-1-one crystal is discussed by relating to its molecular packing in the crystal.

Lithium complexation of configurational isomers of tetra-aza macrocycle containing 2,2′-bipyridine. X-Ray molecular structure of the trans-isomer of a dibutyl dicyano macrocycle

Two configurational isomers of a dicyano dibutyl tetra-azamacrocycle containing four pyridine rings were obtained. The cis-isomer showed a higher complexing ability toward Li+ and Li+/Na+ selectivity than did the trans-isomer. The trans-isomer, the structure of which was established by X-ray analysis, displayed marked spectral changes due to significant conformational changes upon complexation.

Organometallic compounds. XXXIX: Synthesis and X-ray crystal structure of [4][3][4][3](1,2,3,4)ferrocenophane

Abstract [4][3][4][3](l,2,3,4)FeiTocenophane (I) and some related tetrabridgedferrocenophanes have been synthesized via cyclization of 2-[4][4][3](l,3,4)ferroce acid with polyphosphate ester (PPE). Treatment of 5- [4][4][3](l,3,4)ferrocenophanepropanoic acid with PPE or polyphosphoric acid does not give an additionally bridged compound but a bridge-rearrangement product containing two homoannular rings. The crystal structure of I has been determined by X-ray diffraction. Compound I crystallizes in the monoclinic system, space groupP21/a with unit cell parametersa 17.490(4),b 8.489(1),c 12.157(2) «, β 101.51(1)°, andZ = 4. The two cyclopentadienyl (Cp) rings are in an eclipsed conformation and almost parallel to each other (dihedral angle, 1.1°). The bond lengths and angles in the Cp rings and methylene chains are normal but the distances between the Cp ring and the iron atom are unusually short (1.589 and 1.591 «) in comparison with multibridged ferrocenophanes containing tetramethylene chains.

Structure and properties of a new acceptor molecule including boron atoms : 5,10-dimethyl-5,10-dihydroboranthrene

Abstract A new organic acceptor, 5,10-dimethyl-5,10-dihydroboranthrene (BMBT), was prepared and its molecular structure was determined by X-ray analysis. Redox potential suggests that BMBT is a weak acceptor. A charge transfer between BMBT and TTF was confirmed by the complex formation.

Organometallic compounds : XXXVI. X-ray crystal structure of [4][3][4](1,2,3)Ferrocenophane

Abstract The crystal and molecular structure of [4][3][4](1,2,3)ferrocenophane, a ferrocenophane bridged at three neighbouring positions, has been determined by X-ray diffraction. The compound crystallizes in the orthorhombic system, space group Pcab with unit cell dimensions a  15.973(2), b  17.007(2), c  11.648(1) A, and Z  8. The two cyclopentadienyl rings are nearly eclipsed and the dihedral angle between the two rings is 10.4°. The bond lengths and angles in the cyclopentadienyl rings and methylene chains have been found in almost normal ranges in comparison with multibridged ferrocenophanes already reported.

Mixed alkali effect in ionic conduction of (K+, M+)-β -ferrites (M+: Na+ and Cs+) β -alumina structure

Abstract The ionic conductivities of mixed alkali (K + , M + )-β -ferrites (M + : Na + and Cs + ) with different alkali compositions, K + /M + , were measured. In each system, the ionic conductivity isotherm below 100°C exhibited a shallow minimum at about 0.4 mole fraction of M + ion. However, this mixed alkali effect was much smaller than that in β-ferrite. The excess free energy of mixing (Δ G ex ) was calculated using the activity coefficients of K + and M + ions in the mixed alkali (K + , M + )-β -ferrite. The Δ G ex had a slight negative value in contrast to the large negative value in β phase. This indicates that the interaction between K + and M + ions is very small. Therefore, the mixed alkali effect in β -ferrite is very small.

Crystal structure and mixed alkali effect of (K+, Cs+)-β-ferrite

Abstract Crystal structure determination has been accomplished for (K + 0.3 , Cs + 0.7 )-β-ferrite with β-alumina structure to investigate the mixed alkali effect in ionic conduction. According to the structure of conduction plane, BR sites were occupied by cesium ions and mO sites were occupied by potassium ions. It was concluded that blocking effect of cesium ions in BR sites dominate the mixed alkali effect in this ferrite.

A NOVEL SYNTHETIC METHOD FOR AND THE STRUCTURE OF TETRAKIS(μ-BENZOATO-O:O')-BIS(TRIPHENYLPHOSPHINE OXIDE)DICOPPER(II). OXIDATIVE ADDITION OF DIBENZOYLPEROXIDE TO METALLIC COPPER

Abstract Dibenzoyl peroxide undergoes oxidative addition to metallic copper with triphenylphosphine in a mixed solvent (acetone, dichloromethane and trichloromethane) and affords the binuclear complex [Cu(C6H5COO)2(Ph3PO)]2. Crystals are monoclinic, space group A2/a, with cell parameters, a = 24.337(3), b = 10.566(1), c = 21.579(2) A, β = 93.18(1)°, V = 5540(1) A3, Z = 4, R = 0.042, and R w = 0.044 for 5872 observed reflections. Each copper ion is coordinated by four bridging bidentate benzoate ligands and one triphenylphosphine oxide group to form dimeric binuclear molecules.