Kazumi Nakatsu

Cyanovinylheteroaromatics for Organic Nonlinear Optics

Abstract Effects of various substituents including chromophores on the second harmonic generation (SHG) of Cyanovinylheteroaromatics were examined. The molecular polarizability was calculated by the PPP MO method to correlate SHG responsiveness with chemical structures. 3-[(2-cyano-2-ethoxycarbonyl)ethenyl]indole 8b exhibited good SHG efficiency (PE = 25 U). The X-ray analysis of 8b showed that the crystals belong to novel and the most favorable P1 space group.

X-ray and IR studies on crystal and molecular structure of 4-nitro-2,6-diphenylphenol. Stereochemistry of bifurcated OH⋯π hydrogen bonds

Abstract The crystals of the title compound contain both intra- and inter-molecular OH⋯π hydrogen bonds (the first example of bifurcated OH⋯π bonds), the stereochemistry of which has been elucidated by an X-ray structure analysis; this bifurcated bond is also supported by the observation based on the IR spectrum of the crystals.

Periandrin I, a sweet triterpene-glycoside from periandra dulcis

Abstract Further investigation of the natural sweeteners of Periandra dulcis afforded a new sweet triterpene-glycoside, periandrin I, the structure of which was determined to be 3-,β-O-[β- D -glucuronopyranosyl-(1→2)-β- D -glucuronopyranosyl]-25-al-olean-18(19)-en-30-oic acid by chemical and physicochemical evidence and also by X-ray crystallographic analysis of a derivative.

2,6-Diphenylphenol: a structure containing an intramolecular O–H⋯π hydrogen bond

C~sH~40, orthorhombic, P2~2~21, a = 11.165 (1), b = 18.399 (2), c = 6.368 (1) A, Z = 4, D x = 1.251 gcm -a, #(Mo Ka) = 0.89 cm-k The stereochemistry of the intramolecular O-H...Tt hydrogen bond in the title molecule has been estab- fished by single-crystal X-ray analysis. The hydroxyl H atom is favourably located in the proximity of two of the 2-phenyl C atoms, at distances of 2.43 (4) and 2.40 (4) A, to interact with their 7t electrons. The 2- and 6-phenyl rings are twisted from the phenol ring by 52 and 44 ° respectively. Introduction. Hitherto many spectroscopic studies have been carried out on hydrogen bonds in which 7r electrons are involved as the acceptor base. However, only a few unequivocal X-ray studies on such hydrogen bonds have been reported (Hardy & MacNicol, 1976; Aubry, Protas, Moreno-Gonzalez & Marraud, 1977). To elucidate the stereochemistry of the intramolecular O-H... 7t bond the structure of the present compound was studied by X-ray diffraction. Spectroscopic studies on CC14 solutions of the compound (0ki, Hosoya & Iwamura, 1961; Ueji, Ueda & Kinugasa, 1976) showed an intramo!ecular interaction between the hydroxyl group and the 7t electrons of the o-phenyl group. The IR spectrum of the crystals (CsI disc) indicated a single hydroxyl stretching band at 3524 cm -~, which was red- shifted by 88 cm -~ from that of phenol in a dilute CCI 4 solution. This strongly suggests the presence of an

X-ray molecular structure of the 1:1 adduct of [FeH(CO)4]− and dimethyl acetylenedicarboxylate. η3-[trans-2,3-bis(methoxycarbonyl)acryloyl]tricarbonylferrate

Abstract The crystal structure of a bis(triphenylphosphine)iminium salt of the 1:1 adduct of [FeH(CO) 4 ] − and dimethyl acetylenecarboxylate has been determined from three-dimensional X-ray data collected by the counter method. Single crystals belong to the triclinic space space group P 1 , with two units of [C 36 H 30 NP 2 ] + [C 10 H 7 FeO 8 ] − in a cell of dimensions: a = 13.918(2), b = 15.669(5), c = 9.909(2) A, α = 91.22(3), β = 94.83(2), and γ = 77.62(2)°. The structure was refined to a conventional R of 0.068 for 5373 observed reflections. The resulting structure indicates that the complex anion is η 3 -[ trans -2,3-bis(methoxycarbonyl)acryloyl]tricarbonylferrate, the coordination around the iron atom being described as a considerably distorted trigonal bipyramid. A comparison of the present structure with the structures of related complexes suggests that the η 3 -acryloyl portion is best represented as an intermediate of (η 3 -allyl) with the oxygen atom and (η 2 -olefin + η 1 -acyl). The short Fe-C(acyl) length of 1.897(5) A implies an enhanced back-donation of electrons from the iron atom to the acyl group.

SYNTHESIS OF AZO CHROMOPHORES CONTAINING A PERFLUOROCYCLO-ALKENYL MOIETY AND THEIR SECOND-ORDER OPTICAL NONLINEARITY

Abstract 1,2-Bis[4-[4-[ N -ethyl- N -(2-hydroxyethyl)amino]phenylazo]phenylthio]perfluorocyclopentene, having two independent intramolecular push-pull chromophores in a molecule, showed the highest second-order nonlinear coefficient ( d 33 ) among the cyclobutenyl, -pentenyl, -hexenyl, and cyclopentenyl nitro derivatives in both doped poly(methyl methacrylate) (PMMA) and polycarbonate (PC).

X-ray crystallographic analysis of bis[2-(n-propylmercaptomethyl)pyridine]copper(II) diperchlorate, and spectroscopic and redox properties of its related CuIIN2S2 complexes

Abstract A single-crystal X-ray structure analysis of the title copper(II) complex reveals a structure in which the copper atom is centrosymmetrically coordinated by two pyridyl nitrogen atoms [CuN, 2.015(3) A], two thioether sulfur atoms [CuS, 2.366(1) A], and two oxygen atoms of perchlorate ions [CuO, 2.501(3) A]. The triclinic crystal, space group P 1 , has cell dimensions a = 8.955(1), b = 8.794(1), c = 8.517(1) A, α = 104.37(1), β = 109.723(8), γ = 78.86(1)°, and Z = 1. Block-diagonal least-squares refinement, based on 2444 independent reflections with |Fo| > 3σ(F), yields an R factor of 0.044. Electronic absorption and electron spin resonance spectra, as well as redox potentials (Eo′) of the CuIIN2S2 complexes containing thioether-sulfur and pyridyl-, amino-, or imidazolyl-nitrogen donor atoms, were examined. Both the plots of the wave number of dd band maxima vs. EO′ and of 63 65 Cu-hyper-fine coupling constants |A∥| vs. g∥ exhibited a linear relationship, indicating that π-acceptor property of nitrogen-containing ligands contributes mainly to the properties of these CuIIN2S2 complexes.

Preparation and properties of AzaTCNQ− anion salts and mixed AzaTCNQ−/ TCNQ⨪/TCNQ salts of some tetrakis(isocyanide)rhodium(I) cation, and x-ray crystal structure of the AzaTCNQ−-tetrakis(2,6-dimethylphenylisocyanide)rhodium(I)+ salt

Abstract The following ATCNQ − salts and mixed ACTNQ − / TCNQ ⨪ /TCNQ salts (ATCNQ − = 4-dicyanomethylenepyridinium dicyanomethylide, so-called aza-tetracyanoquinodimethan anion; TCNQ = 7,7,8,8-tetracyano- p -quinodimethan) of tetrakis(isocyanide)rhodium(I) cation were prepared; [Rh(RNC) 4 ] + ATCNQ − (R = C 6 H 5 , 2,6-Me 2 C 6 H 3 , and 2,4,6-Me 3 C 6 H 2 ), [Rh(RNC) 4 ] + (ATCNQ − ) n (TCNQ) ⨪ ) 1-n (R = 2,6-Me 2 C 6 H 3 , n = 0.2; R = C 6 H 5 and 2,4,6-Me 3 C 6 H 2 , n = 0.3), and [Rh(RNC) 4 ] + (ATCNQ − ) a9 (TCNQ ⨪ ) 0.1 (TCNQ) 0.8 (R = 2,6-Me 2 C 6 H 3 and 2,4,6-Me 3 C 6 H 2 ). Of these salts, [Rh(2,6-Me 2 C 6 H 3 NC) 4 ] + (ATCNQ − / TCNQ ⨪ and [Rh(2,6-Me 2 C 6 H 3 NC) 4 ] + (ATCNQ − )/ TCNQ ⨪ /TCNQ) exhibit electrical resistivities of ∼1 X 10 5 Ωcm as compacted samples at 25 °C and behave as typical semi-conductors, while the resistivities of other salts are larger than 1 X 10 9 Ωcm. Electronic absorption spectra and magnetic susceptibilities of the salts are discussed in terms of stackings of TCNQ ⨪ , TCNQ, and ATCNQ − in the solid state. The crystal structure of [Rh(2,6-Me 2 C 6 H 3 NC) 4 ] + ATCNQ − was determined by single-crystal X-ray diffraction. The triclinic crystal, space group P 1 , has cell dimensions a = 10.964(2), b = 12.768(2), c = 8.375(1) A, α = 102.03(2), β = 88.84(2), gg = 112.07(2)°, and Z = 1, where the orientation of the ATCNQ − anion moiety is disordered with respect to the pyridinium ring. Least-squares refinement, based on 4094 independent reflections with ∣ F o ∣ > 3σ( F ), yielded an R factor of 0.052

X-ray molecular structure of tetracarbonyl (S,S-dimethyl- sulfonium 2-picolinylmethylide) tungsten (O)

Abstract The structure of the title compound has been determined by single-crystal X-ray analsis. The crystals contain moneric units and are of space group p2 1 /c, with Z = 4 in each unit cell of dimiensions: a = 7.658(1), b = 11.881(2), c = 17.233(2) », β = 103.51(1)°. The structure was refined to a conventional R factor of 0.042 using 2542 observed ( F o > 3γ( F )) reflections. The ylide ligand coordinates to tungsten through the pyridine nitrogen and carbonyl oxygen atoms, forming a distorted octahedral geometry around the metal atom.

The Structure of Neplanocin C

Abstract The molecular and crystal structure of neplanocin C(3), C11H13N5O4 M.W. = 279.26, has been determined by X-ray anlysĩs. The space group is P21 with a=16.381(2), b=8.210(1), c=9.127(1) A, β=105.31(1)° and z=4. The structure was solved by direct method, and least-squares refinement using 2093 reflections with |Fo|>3σ(F) led to the final R value of 0.0772. The sugar puckering of the two crystal-lographically independent molecules is C(2′)-exo-C(3′)-endo, and the torsion angles about the N(9)-C(1′) bond are 22.8(6) and 28.7(6)°, respectively (anti conformation).