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Molecular Structure and Spectroscopy
Published in W. M. Haynes, David R. Lide, Thomas J. Bruno, CRC Handbook of Chemistry and Physics, 2016
W. M. Haynes, David R. Lide, Thomas J. Bruno
Other conjugative substituents excluded. TCNQ is tetracyanoquinodimethane. No difference detected between C2 C3 and C3 C4 bonds. Derived from neutron diffraction results only. Nsp3: pyramidal; mean valence angle at N is in range 108-114º. Nsp2: planar; mean valence angle at N is 117.5º. Cyclic and acyclic peptides. See R. H. Blessing, J. Am. Chem. Soc., 1983, 105, 2776. See L. Lebioda, Acta Crystallogr., 1980, B36, 271. n = 3 or 4, i.e. tri- or tetra-substituted ureas. Overall value also includes structures with mean valence angle at N in the range 115-118º. See F. H. Allen and A. J. Kirby, J. Am. Chem. Soc., 1984, 106, 6197. See A. J. Kirby, `The Anomeric Effect and Related Stereoelectronic Effects at Oxygen,' Springer, Berlin, 1983. See B. Fuchs, L. Schleifer, and E. Tartakovsky, Nouv. J. Chim., 1984, 8, 275. See S. C. Nyburg and C. H. Faerman, J. Mol. Struct., 1986, 140, 347. Sample dominated by P-CH3 and P-CH2-C. Sample dominated by C* = methyl. See A. Kalman, M. Czugler, and G. Argay, Acta Crystallogr., 1981, B37, 868. Bimodal distribution resolved into 22 `short' bonds and 5 longer outliers. All 24 observations come from BUDTEZ. `Long' O-H bonds in centrosymmetric O---H---O H-bonded dimers are excluded. N-N bond length also dependent on torsion angle about N-N bond and on nature of substituent C atoms; these effects are ignored here. N pyramidal has average angle at N in range 100-113.5º; N planar has average angle of 117.5º. See R. R. Holmes and J. A. Deiters, J. Amer. Chem. Soc., 1977, 99, 3318. No detectable variation in S=O bond length with type of C-substituent.
Synthesis and self-assembly properties of thiacrown-cyclized tetrathiafulvalene organogelators
Published in Journal of Sulfur Chemistry, 2023
Ruibin Hou, Chao Xu, Jiajia Yan, Yan Xia, Dongfeng Li
The electron-donating ability of gelator 1 was investigated by ultraviolet (UV)–visible absorption spectroscopy. As a classical electron-acceptor compound, 7,7,8,8-tetracyanoquinodimethane (TCNQ) can form a charge-transfer (CT) complex in solution. After 1.0 equiv of TCNQ was added, the maximum absorption peaks appeared at 669, 748, and 850 nm (Figure 2). According to a previous study [25], the absorption peak at 669 nm was TTF•+, while the absorption peaks at 748 and 850 nm were TCNQ−. CT-complex formation can be confirmed by color comparison of the solution before and after addition of TCNQ to the CH2Cl2 solution of target compound 1.