[closo-B10H10]2- as a structural element for quadrupolar liquid crystals: a new class of liquid crystalline NLO chromophores

被引:40
作者
Jankowiak, Aleksandra [1 ]
Balinski, Andrzej [1 ]
Harvey, James E. [1 ]
Mason, Kristein [1 ]
Januszko, Adam [1 ]
Kaszynski, Piotr [1 ,2 ]
Young, Victor G., Jr. [3 ]
Persoons, Andre [4 ]
机构
[1] Vanderbilt Univ, Dept Chem, Organ Mat Res Grp, Nashville, TN 37235 USA
[2] Univ Lodz, Fac Chem, PL-91403 Lodz, Poland
[3] Univ Minnesota, Dept Chem, Xray Crystallog Lab, St Paul, MN 55455 USA
[4] Univ Louvain, Dept Chem, B-3001 Louvain, Belgium
基金
美国国家科学基金会;
关键词
NONLINEAR-OPTICAL PROPERTIES; NUCLEAR-MAGNETIC-RESONANCE; HYPER-RAYLEIGH SCATTERING; CHARGED AROMATIC DONORS; 3-DIMENSIONAL AROMATICITY; CONFORMATIONAL-ANALYSIS; BORANES; DERIVATIVES; CHEMISTRY; BORON;
D O I
10.1039/c2tc00547f
中图分类号
T [工业技术];
学科分类号
08 ;
摘要
Several electrically neutral, highly quadrupolar derivatives of the [closo-B10H10](2-) cluster (I) substituted in the apical positions with onium fragments derived from 4-alkoxypyridine, 4-pentylthian, 4-pentylquinuclidine, or dinitrogen were synthesized from the parent cluster in 2-5 steps, and their thermal, structural, photophysical and dielectric properties were investigated. Only derivatives 2, containing thianium and alkoxypyridinium substituents with linear alkyl chains, exhibit liquid crystalline behavior and form a nematic phase. alpha-Branching of the alkoxy chain leads to marked destabilization of both crystalline and nematic phases, which suggests the importance of polar interactions in phase stabilization of these compounds. Derivatives 2 and 3 with one pi and one sigma substituent, Q(+), exhibit a directional cluster-to-Q charge transfer and increase of the net electric dipole moment to mu(e) = 17.9 D for 2a upon photo-excitation. They are weak fluorophores (Phi(f) = 2-7%). Detailed investigation of 4-heptyloxypyridinium derivative 2b revealed that it exhibits a nematic phase above 100 degrees C with Delta(epsilon) = +1.3 (130 degrees C), and a moderate negative solvatochromism. Hyper-Rayleigh scattering measurement gave beta(HRS) = 45 +/- 10 x 10(-30) esu at 1064 nm. In solutions, and presumably in the melt, it exists as a mixture of interconverting trans and cis isomers at about 4 : 1 ratio with Delta G(298) = 0.82 +/- 0.06 kcal mol(-1) and Delta G(298)(double dagger) = 25.3 +/- 0.6 kcal mol(-1) established by VT NMR methods.
引用
收藏
页码:1144 / 1159
页数:16
相关论文
共 74 条
[1]   3-DIMENSIONAL AROMATICITY OF POLYHEDRAL BORANES [J].
AIHARA, J .
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, 1978, 100 (11) :3339-3342
[2]   Polyhedral-based nonlinear optical materials. 2. Theoretical investigation of some new high nonlinear optical response compounds involving polyhedral bridges with charged aromatic donors and acceptors [J].
Allis, DG ;
Spencer, JT .
INORGANIC CHEMISTRY, 2001, 40 (14) :3373-3380
[3]   Polyhedral-based nonlinear optical materials. Part 1. Theoretical investigation of some new high nonlinear optical response compounds involving carboranes and charged aromatic donors and accepters [J].
Allis, DG ;
Spencer, JT .
JOURNAL OF ORGANOMETALLIC CHEMISTRY, 2000, 614 :309-313
[4]   1-Bromo-3,3-bis(2-bromoethyl)alkanes: Precursors to 4-substituted quinuclidines and 1-phospha-bicyclo[2.2.2]octanes [J].
Bairamov, KA ;
Douglass, AG ;
Kaszynski, P .
SYNTHETIC COMMUNICATIONS, 1998, 28 (03) :527-540
[5]  
Barlow S., 2007, FUNCTIONAL ORGANIC M, P393
[6]   QUADRATIC HYPERPOLARISABILITY OF SULFUR-CONTAINING SYSTEMS [J].
BARZOUKAS, M ;
JOSSE, D ;
ZYSS, J ;
GORDON, P ;
MORLEY, JO .
CHEMICAL PHYSICS, 1989, 139 (2-3) :359-367
[7]   DENSITY-FUNCTIONAL THERMOCHEMISTRY .3. THE ROLE OF EXACT EXCHANGE [J].
BECKE, AD .
JOURNAL OF CHEMICAL PHYSICS, 1993, 98 (07) :5648-5652
[8]   EXPERIMENTAL-DETERMINATION OF THE CONFORMATIONAL FREE-ENERGY - ENTHALPY, AND ENTROPY DIFFERENCES FOR ALKYL-GROUPS IN ALKYLCYCLOHEXANES BY LOW-TEMPERATURE C-13 MAGNETIC-RESONANCE SPECTROSCOPY [J].
BOOTH, H ;
EVERETT, JR .
JOURNAL OF THE CHEMICAL SOCIETY-PERKIN TRANSACTIONS 2, 1980, (02) :255-259
[9]   CONFORMATIONAL-ANALYSIS OF AMINOCYCLOHEXANE USING N-15 NUCLEAR MAGNETIC-RESONANCE AT LOW-TEMPERATURE [J].
BUCHANAN, GW ;
WEBB, VL .
TETRAHEDRON LETTERS, 1983, 24 (42) :4519-4520
[10]   SYNTHESIS AND REACTIONS OF CHIRAL SULFONIUM YLIDS [J].
CAMPBELL, SJ ;
DARWISH, D .
CANADIAN JOURNAL OF CHEMISTRY-REVUE CANADIENNE DE CHIMIE, 1974, 52 (16) :2953-2959