Chemical bond analysis of the correlation between crystal structure and nonlinear optical properties of complex crystals

Second order nonlinear optical (NLO) properties of single crystals with complex structures are studied, from the chemical bond viewpoint. Contributions of each type of constituent chemical bond to the total linearity and nonlinearity are calculated from the actual crystal structure, using the chemical bond theory of complex crystals and the modified bond charge model. We have quantitatively proposed certain relationships between the crystal structure and its NLO properties. Several relations have been established from the calculation. Our method makes it possible for us to identify, predict and modify new NLO materials according to our needs. (C) 1999 Elsevier Science B.V. All rights reserved.

Synthesis, properties and crystal structure of charge-transfer salt (DBTTF)(6)HSiMo12O40H2O

Charge-transfer salt (DBTTF)(6)HSiMo(12)O(40)4H(2)O was synthesized by electrocrystallization and characterized by IR spectrum and electronic spectrum. Its magnetic property, conductivity and crystal structure were determined. The title compound consists of heteropoly anions, water molecules and DBTTF columns which are formed by repeated arrangement of tetramer (DBTTF), in the direction of 15 degrees to the a axis in the tunnel constituted by the anions and other type of DBTTF. The title compound is paramagnetic and semiconducting. (C) 1998 Elsevier Science Ltd. All rights reserved.

Synthesis, crystal structure and properties of (Z)-3-triphenylstannyl-1,1-diphenyl propenol

Five new organotin compounds were synthesized and characterized, X-ray crystal structure analysis of (Z)-3-triphenylstannyl-1,1-diphenyl propenol was performed, The crystal belongs to space group P2(1)/n. The cell parameters are: a = 1.235 7(2) nm, b = 0.987 4(2) nm, c = 2.208 1(4) nm, beta = 95.23(3)degrees, V = 2.683 0(9) nm(3), Z = 4, R = 0.027 9, R-w = 0.064 5. The tin atom of the molecule exists in a distorted tetrahedron, Z isomer of double bond is obtained.

Synthesis, electrical properties and crystal structure of a new radical-ion salt based on pi-extended bis(TTF) and a Keggin heteropolymolybdate

By electrocrystallization of 2,6-[4,5-bis(n-butylsulfanyl)-1,3-dithiol-2-ylidene]-4,8-bis(6-iodo-n-hexyloxy)-1,3,5,7-tetrathia-s-indacene (BHBDTI) and [NBu4](4)[SiMo12O40] in the mixed solvent CHCl2CH2Cl and CH3CN, the new radical-ion salt [C42H60Cl2O2S12](2)[SiMo12O40] was prepared. It was characterized by means of IR and ESR spectroscopy and X-ray diffraction. In the crystal structure, organic radical dications and silicomolybdate anions are alternatively arranged along the a axis to form a 1-D conducting layer. The organic layer consists of two isolated groups of BHBDTI divided by the (011) plane without short interatomic contacts. However, in each group, BHBDTI molecules associate with each other in a head to tail manner running along the [011] direction and face-to-face overlapping with a relative shift by approximately one TTF subunit along the long axis of the molecule and a slight shift along the short axis of the molecule with significantly short S ... S contacts. The room-temperature d.c. conductivity determined by the two-probe method is 10(-4) S cm(-1), suggesting that the compound is a semiconductor.

Synthesis and crystal structure of a polymeric erbium(III)-sodium(I) coordination complex of picolinic acid N-oxide

A new Er(III)-Na(I) coordination polymer of stoichiometry [NaEr2L5(H2O)(6)(NO3)](NO3). 3.5H(2)O (HL = picolinic acid N-oxide) has been synthesized and characterized by single-crystal X-ray analysis. Crystals are triclinic, P (1) over bar with a = 9.823(2), b = 12.453(2), c = 20.643(4) Angstrom; alpha = 98.49(3), beta = 101.40(3), gamma = 108.69(3)degrees; V = 2284(1) Angstrom(3); Z = 2. Of the two independent eight-coordinate erbium(III) ions in this complex, one is surrounded by four bidentate chelating L ligands, and the other by one bidentate chelating L ligand, four aqua ligands and two anti-carboxylate oxygen atoms from two neighboring [ErL4] units. The sodium(I) ion is in a distorted octahedral environment, being coordinated by a unidentate nitrate anion, three aqua ligands and two anti-carboxylate oxygen atoms from two adjacent [ErL4] units. The complex is built from zigzag chains of syn-anti carboxylate-bridged erbium(III) moieties directed in the a direction, which are cross-linked pairwise by aqua-bridged dimeric sodium(I) units. The resulting composite polymeric chains are further connected by hydrogen bonds to form a three-dimensional network.

Synthesis, properties and crystal structure of organic-inorganic radical salt (DBTTF)(6)HPMo12O40 center dot 2H(2)O

Organic-inorganic radical salt (DBTTF)(6)PMo12O40 . 2H(2)O was synthesized by electrocrystallization and characterized by IR spectrum, electronic spectrum and ESR technology, Its magnetic property, conductivity and crystal structure were determined. The title compound crystallized in a triclinic system with P1 space group, a = 1.378 7(7), b = 1.420 4 (2), c = 1.570 2(2) nm, alpha = 104.57(1)degrees, beta = 103.41(2)degrees, gamma = 95.80(2)degrees, V = 2.853(2) nm(3) Z = 1 and a final R = 0.072 7.

Synthesis and crystal structure of chiral bis(cyclopentadienyl) samarium Schiff base complexes bearing intramolecular C-C bond formation and hydrogen transfer

SmCl3, reacted with CpNa (Cp = Cyclopentadienyl) in the ratio of 1:3 in THF, which then was reacted with (S)-(+)-N-1-(phenylethyl) salicylideneamine/toluene to yield the title complex, [GRAPHICS] The X-ray crystal structure determination of the title complex reveals that 1 is a dimer with intramolecular C-C bond formation and hydrogen transfer, which leads to the configuration turnover of the carbon atom at the benzyl position of the ligand, while those of the newly formed asymmetric centers may have either Ii or S type configurations. (C) 1998 Elsevier Science Ltd. All rights reserved.

Synthesis of the first mono(cyclopentadienyl)lanthanide Schiff base complex bearing C-2-symmetric tetradentate ligand: crystal structure of [(eta(5)-C5H5)Yb(mu-OC20H20N2O)](2)(mu-THF)(THF)

Reaction of YbCl3 with 3 equimolar CpNa (Cp = cyclopentadienide) in THF, followed by treatment with trans-(+/-)-N,N'-bis(salicylidene)-1,2-cyclohexanediamine led to the isolation of first mono(cyclopentadienyl) lanthanide Schiff base complex, [(eta(5)-C5H5)Yb(mu-OC20H20N2O)](2) (mu-THF)(THF) (1). The molecular structure of 1 shows that it is a dimer in which the two [(eta(5)-C5H5)Yb(mu-OC20H20N2O)] units connecting via a bridging THF oxygen and two bridging oxygen atoms from Schiff base ligands. (C) 1998 Elsevier Science S.A.

Synthesis and crystal structure of aluminium complex with 3-hydroxyflavone

[Al(C15H9O3)(3)](2) . 2CHCl(3) . 8H(2)O was synthesized, and its crystal structure was determined. It belongs to trigonal system, R3, a=b=1. 655 8(3) nm, c=3. 646 5(20) nm, alpha = beta = 90 degrees, gamma = 120 degrees, V = 8. 656 08(0. 005 86) nm(3). D-c = 1.45 g/cm(3), mu(Mo K alpha) = 3. 20 cm(-1), F (000) = 3 924. The crystal structure was solved by Patterson and Fourier techniques, and refined by a block-diagonal least-squares method. A total of 3 737 independent intensity data were collected, of which 1 033 with I greater than or equal to 3 sigma(I-0) were observed, R = 0. 091 8, Rw=0. 091 8. Al3+ ion was 6-coordinated, bound to six oxygen atoms from three 3-hydroxyflavones to form a distortional coordination octahedron.

Synthesis and X-ray crystal structure of [(eta(5)-C5H5)Sm(mu-OC20H20N2O)](2)(mu-THF)(THF)(2): Mono(cyclopentadienyl)lanthanide complex bearing a C-2-symmetric tetradentate Schiff-base ligand

Cp2SmCl(THF) reacts with 0.5 equivalent disodium salts of trans-(+/-)-N,N'-bis(salicylidene)-1,2-cyclohexanediamine give the title complex [(eta(5)-C5H5)Sm(mu-OC20H20N2O)](2)(mu-THF)(THF)(2) (1). X-ray crystal determination shows that the molecule is a dimer, in which two (eta(5)C(5)H(5))Sm(mu-OC20H20N2O) units are connected via a THF oxygen and two bridging oxygen atoms of Schiff base ligands. The average Sm-C distance is 2.78(7) Angstrom, while those of Sm-O (bridging THF oxygen) and Schiff base oxygens are 2.79(3) and 2.43(4) Angstrom; respectively. (C) 1998 Elsevier Science Ltd. All rights reserved.

Crystal structure and mechanism of (Z)-1-[2-(phenyl-bromide-chloride)vinyl]-1-cyclohexanol

The crystal structure and mechanism of the title molecule are described. This crystal is orthorhombic, belonging to space group PC21/B with a=1,002 1(2) nm, b=1.483 0(3) nm, c=2.173 6(4) nm, V=3.230 39(2) nm(3), Z=2, D-c=1.80 g/cm(3), R=0.069 3. The structure was solved by direct method. The tin atom of the title compound exists in two distorted-trigonal-bipyramidal geometry, defined by two carbon, one bromide, one chloride and one oxygen atoms leading to a five-membered chelate ring. In the structure, the five-membered ring containing the intermolecular O-->Sn has a half chair conformation.

Synthesis, properties and crystal structure of a heteropoly compound containing titanium

K4H2CoW12O40. 2Ti02 . 9H(2)O crystallizes from an aqueous solution of Na2WO4, Co(OAc)(2) and Ti(SO4)(2). The compound has very similar i.r. and u.v. spectra to those of [CoW12O40](6-) and [CoW11TiO40](8-) but its polarographic behaviour is different from that of [CoW11TiO40](8-) and exhibits only reduction of tungsten(VI). A single crystal structural analysis indicates that this compound consists of the heteropolyanion [CoW12O40](6-), titanium-oxygen chain, potassium ions and water molecules.

Synthesis, crystal structure and magnetic properties of a series of polymeric lanthanoid-copper complexes [Ln(2)Cu(3){O(CH2-CO2)(2)}(6)].nH(2)O (Ln=La, Nd, n=9; Ln=Er, n=6)

The reaction of diglycolic acid, O(CH2CO2H)(2), with Cu(NO3)(2) . H2O and lanthanoid nitrate hydrate produces a series of novel Ln-Cu mixed metal complexes, [Ln(2)CU(3){O(CH2CO2)(2)}(6)]. nH(2)O (Ln = La, Nd, n = 9; Ln = Er, n = 6), which have been characterized by elemental analysis, i.r. spectroscopy, magnetic measurements and X-ray crystallography. The Ln(3+) and Cu2+ ions are connected by the carboxylate groups of the ligands, resulting in the formation of a complicated network.

Crystal structure of a Pr-III complex with a novel macrocyclic ligand

The crystal structure of a novel macrocyclic ligand complex of Pr-III, C112H178O52N8S4Pr2, [Pr2L2(HL)(2)(H2O)(6)]. 22H(2)O is reported. The macrocyclic ligand has pendant acetic acid through which the ligand is coordinated to the Pr-III ion. For the dimeric unit, [Pr2L2(HL)(2)(H2O)(6)], two Pr-III ions are connected by two bridging-chelating carboxyl groups and two bridging carboxyl groups of the ligands, and each Pr-III ion is also bonded to a unidentate carboxyl group of the ligand and three water molecules. The dimeric units are bridged by four ligands through their carboxyl groups to form an infinite one-dimensional chain. The coordination number of the Pr-III ion is nine, with a distorted tricapped trigonal prismatic configuration. (C) 1997 Elsevier Science Ltd.

The crystal structure and drawing-induced polymorphism in poly(aryl ether ketone)s .2. Poly(ether ether ketone ketone), PEEKK

The crystal structure, morphology and polymorphism induced by uniaxial drawing of poly(ether ether ketone ketone) [PEEKK] have been studied by transmission electron microscopy (TEM), electron diffraction (ED) and wide angle X-ray diffraction (WAXD). On the basis of WAXD and ED patterns,the crystal structure of unoriented PEEKK is determined to have two-chain orthorhombic packing with unit cell parameters of a 0.772 nm, b = 0.600 nm, c = 1.004 nm (form I), A stress-induced crystal modification (form II) is identified and found to possess a two-chain orthorhombic lattice with unit cell dimensions of a = 0.461 nm, b = 1.074 nm, c = 1.080 nm. The 7.5% increase in c-axis dimension for form II is attributed to an overextended chain conformation, arising from extensional deformation during uniaxial drawing and fixed ''in-situ'' through strain-induced crystallization. The average ether-ketone bridge bond angles in form II crystal are determined to be 148.9 degrees by using standard bond lengths. The crystal morphology of PEEKK bears a great similarity to that of PEEK. The crystals grow in the form of spherulites and have the b-axis of unit cell radial. The effects of draw rate on strain-induced crystallization and induction of form II structure are also discussed.