Studies on Aromatic Trichromophore Systems Incorporating Anthracene Moieties. III. Crystal Structures of 2-(9-Anthryl)-1-(9-anthrylmethyl)ethyl 2-(9-Anthryl)ethyl Succinate (A2A) and 2-(9-Anthryl)ethyl Acetate (AM) and Their Fluorescence in the Solid State

1996 ◽  
Vol 49 (1) ◽  
pp. 13 ◽  
Author(s):  
M Cotrait ◽  
H Allouchi ◽  
P Marsau ◽  
A Nourmamode ◽  
S Grelier ◽  
...  

The structures of 2-(9-anthryl)-1-(9-anthrylmethyl)ethyl 2-(9 anthryl )ethyl succinate (A2A) and 2-(9-anthryl)ethyl acetate (AM) have been determined by X-ray diffraction, and the molecular fluorescence of the crystals has been established. The A2A crystal is triclinic while the AM crystal is monoclinic. A2A: Pī , a 18.514(5), b 11.802(3), c 10.836(3) Ǻ; α 99.63(2), β 85.75(2), γ 79.67(2)°, R 0.053 for 3547 observed reflections. AM: P21/c, a 12.566(2), b 12.991(2), c 8.805(2) Ǻ, β 97.84(1)°, R 0.040 for 1519 observed reflections. For the A2A molecule as for the previously studied A2PHEN and A2SC (see Part II), the bisanthracene moiety and a large part of the ester chain show similar conformations. The crystal cohesion is due to numerous van der Waals interactions in both compounds and to π intermolecular overlap between the anthracene moieties of neighbouring molecules of AM. The fluorescence emission of the AM crystal is of excimer type and correlates with the intermolecular stacking of the anthracene rings. In contrast, the emission from the A2A crystal was found to be very weak and with some similarity with the emission of the dilute solution. This is probably due to defects, not accounted for by the X-ray determination, permitting intramolecular interactions in the solid.


1994 ◽  
Vol 47 (3) ◽  
pp. 423 ◽  
Author(s):  
M Cotrait ◽  
P Marsau ◽  
L Kessab ◽  
S Grelier ◽  
A Nourmamode ◽  
...  

The structures of 2-(9-anthryl)-1-(9-anthrylmethyl)ethyl 2-(9-phenanthryl)ethyl succinate (A2PHEN) and 2-(9-anthryl)-1-(9-anthrylmethyl)ethyl methyl succinate (A2SC) have been determined by X-ray diffraction, and the molecular fluorescence of the crystals has been established. The two crystals are monoclinic. A2PHEN: C 2/c, a 39.47(1), b 9.718(2), c 19.924(8) Ǻ; β 97.81(3)°; R 0.036 for 2903 unique reflections. A2SC: P 21/c, a 16.248(2), b 10.325(2), c 18.052(2) Ǻ. β 114.20(3)°; R 0.044 for 2586 unique reflections. For both structures, the bisanthracene moiety and a large part of the ester chain show similar conformations. The crystal cohesion is due to intermolecular π overlapping between one of the anthracene components of the bichromophore moiety and to numerous van der Waals interactions. No intramolecular interactions between the phenanthrene and the anthracene moieties are observed in A2PHEN. The fluorescence emissions of A2PHEN and A2SC are of excimer type, and correlate well with the intermolecular interactions between the anthracene rings.



2009 ◽  
Vol 65 (5) ◽  
pp. 639-646 ◽  
Author(s):  
Edward E. Ávila ◽  
Asiloé J. Mora ◽  
Gerzon E. Delgado ◽  
Ricardo R. Contreras ◽  
Luis Rincón ◽  
...  

The molecular and crystalline structure of ethyl 1′,2′,3′,4′,4a′,5′,6′,7′-octahydrodispiro[cyclohexane-1,2′-quinazoline-4′,1′′-cyclohexane]-8′-carbodithioate (I) was solved and refined from powder synchrotron X-ray diffraction data. The initial model for the structural solution in direct space using the simulated annealing algorithm implemented in DASH [David et al. (2006). J. Appl. Cryst. 39, 910–915] was obtained performing a conformational study on the fused six-membered rings of the octahydroquinazoline system and the two spiran cyclohexane rings of (I). The best model was chosen using experimental evidence from 1H and 13C NMR [Contreras et al. (2001). J. Heterocycl. Chem. 38, 1223–1225] in combination with semi-empirical AM1 calculations. In the refined structure the two spiran rings have the chair conformation, while both of the fused rings in the octahydroquinazoline system have half-chair conformations compared with in-vacuum density-functional theory (DFT) B3LYP/6-311G*, DFTB (density-functional tight-binding) theoretical calculations in the solid state and other related structures from X-ray diffraction data. Compound (I) presents weak intramolecular hydrogen bonds of the type N—H...S and C—H...S, which produce delocalization of the electron density in the generated rings described by graph symbols S(6) and S(5). Packing of the molecules is dominated by van der Waals interactions.



2014 ◽  
Vol 70 (11) ◽  
pp. 1025-1028
Author(s):  
Hong Shen

The title CdIIcoordination polymer, [Cd(C10H8O4)(C12H12N6)0.5(H2O)]n, has been obtained by the hydrothermal method and studied by single-crystal X-ray diffraction, elemental analysis, thermogravimetric analysis, IR spectroscopy and fluorescence spectroscopy. The compound forms a novel three-dimensional framework with 3,8-connected three-dimensional binodal {4.52}2{42.510.612.7.83} topology. An investigation of its photoluminescence properties shows that the compound exhibits a strong fluorescence emission in the solid state at room temperature.



2020 ◽  
Vol 235 (1-2) ◽  
pp. 47-51
Author(s):  
Arpita Dutta ◽  
Suven Das ◽  
Purak Das ◽  
Suvendu Maity ◽  
Prasanta Ghosh

AbstractN-(N-benzoyl glycinyl)-N,N′-dicyclohexylurea was synthesised by conjugating N-benzoyl glycine and dicyclohexylcarbodiimide (DCC) using triethylamine as base catalyst. A single crystal X-ray diffraction study reveals that the compound self-assembles into a supramolecular sheet structure by intermolecular N–H · · · O, C–H · · · O hydrogen bonding and non-bonding van der Waals interactions. A high resolution transmission electronic microscopic (HR-TEM) image of the compound exhibits formation of fibrils in the solid state.



Molecules ◽  
2019 ◽  
Vol 24 (14) ◽  
pp. 2552 ◽  
Author(s):  
Andrea Previtali ◽  
Elena Lucenti ◽  
Alessandra Forni ◽  
Luca Mauri ◽  
Chiara Botta ◽  
...  

Organic room temperature persistent luminescence is a fascinating but still largely unexplored phenomenon. Cyclic-triimidazole and its halogenated (Br, I) derivatives have recently revealed as intriguing phosphors characterized by multifaceted emissive behavior including room temperature ultralong phosphorescence (RTUP) associated with the presence of H-aggregates in their crystal structure. Here, we move towards a multicomponent system by incorporating a fluoropyridinic fragment on the cyclic-triimidazole scaffold. Such chromophore enhances the molecular properties resulting in a high photoluminescence quantum yield (PL QY) in solution but preserves the solid-state RTUP. By means of X-ray diffraction (XRD) analysis, theoretical calculations, steady-state and time-resolved spectroscopy on solutions, polymethylmethacrylate (PMMA) blends and crystals, the nature of the different radiative deactivation channels of the compound has been disclosed. In particular, the molecular fluorescence and phosphorescence, this latter observed in frozen solution and in PMMA blends, are associated to deactivation from S1 and T1 respectively, while the low energy RTUP, observed only for crystals, is interpreted as originated from H aggregates.



Author(s):  
Kenneth M. Richter ◽  
John A. Schilling

The structural unit of solid state collagen complexes has been reported by Porter and Vanamee via EM and by Cowan, North and Randall via x-ray diffraction to be an ellipsoidal unit of 210-270 A. length by 50-100 A. diameter. It subsequently was independently demonstrated by us in dog tendon, dermis, and induced complexes. Its detailed morphologic, dimensional and molecular weight (MW) aspects have now been determined. It is pear-shaped in long profile with m diameters of 57 and 108 A. and m length of 263 A. (Fig. 1, tendon, KMnO4 fixation, Na-tungstate; Fig. 2a, schematic of unit in long, C, and x-sectional profiles of its thin, xB, and bulbous, xA portions; Fig. 2b, tendon essentially unmodified by ether and 0.4 N NaOH treatment, Na-tungstate). The unit consists of a uniquely coild cable, c, of ṁ 22.9 A. diameter and length of 2580-3316 A. The cable consists of three 2nd-strands, s, each of m 10.6 A.



Author(s):  
F. Ma ◽  
S. Vivekanand ◽  
K. Barmak ◽  
C. Michaelsen

Solid state reactions in sputter-deposited Nb/Al multilayer thin films have been studied by transmission and analytical electron microscopy (TEM/AEM), differential scanning calorimetry (DSC) and X-ray diffraction (XRD). The Nb/Al multilayer thin films for TEM studies were sputter-deposited on (1102)sapphire substrates. The periodicity of the films is in the range 10-500 nm. The overall composition of the films are 1/3, 2/1, and 3/1 Nb/Al, corresponding to the stoichiometric composition of the three intermetallic phases in this system.Figure 1 is a TEM micrograph of an as-deposited film with periodicity A = dA1 + dNb = 72 nm, where d's are layer thicknesses. The polycrystalline nature of the Al and Nb layers with their columnar grain structure is evident in the figure. Both Nb and Al layers exhibit crystallographic texture, with the electron diffraction pattern for this film showing stronger diffraction spots in the direction normal to the multilayer. The X-ray diffraction patterns of all films are dominated by the Al(l 11) and Nb(l 10) peaks and show a merging of these two peaks with decreasing periodicity.



Author(s):  
A. Kareem Dahash Ali ◽  
Nihad Ali Shafeek

This study included the fabrication of    compound (Tl2-xHgxBa2-ySryCa2Cu3O10+δ) in a manner solid state and under hydrostatic pressure ( 8 ton/cm2) and temperature annealing(850°C), and determine the effect of the laser on the structural and electrical properties elements in the compound, and various concentrations of x where (x= 0.1,0.2,0.3 ). Observed by testing the XRD The best ratio of compensation for x is 0.2 as the value of a = b = 5.3899 (A °), c = 36.21 (A °) show that the installation of four-wheel-based type and that the best temperature shift is TC= 142 K  .When you shine a CO2 laser on the models in order to recognize the effect of the laser on these models showed the study of X-ray diffraction of these samples when preparing models with different concentrations of the values ​​of x, the best ratio of compensation is 0.2 which showed an increase in the values ​​of the dimensions of the unit cell a=b = 5.3929 (A °), c = 36.238 (A°). And the best transition temperature after shedding laser is TC=144 K. 



2019 ◽  
Vol 15 (8) ◽  
pp. 850-862
Author(s):  
Mirthala Flores-García ◽  
Juan Manuel Fernández-G. ◽  
Cristina Busqueta-Griera ◽  
Elizabeth Gómez ◽  
Simón Hernández-Ortega ◽  
...  

Background: Ischemic heart disease, cerebrovascular accident, and venous thromboembolism have the presence of a thrombotic event in common and represent the most common causes of death within the population. Objective: Since Schiff base copper(II) complexes are able to interact with polyphosphates (PolyP), a procoagulant and potentially prothrombotic platelet agent, we investigated the antiplatelet aggregating properties of two novel tridentate Schiff base ligands and their corresponding copper( II) complexes. Methods: The Schiff base ligands (L1) and (L2), as well as their corresponding copper(II) complexes (C1) and (C2), were synthesized and characterized by chemical analysis, X-ray diffraction, mass spectrometry, and UV-Visible, IR and far IR spectroscopy. In addition, EPR studies were carried out for (C1) and (C2), while (L1) and (L2) were further analyzed by 1H and 13C NMR. Tests for antiplatelet aggregation activities of all of the four compounds were conducted. Results: X-ray diffraction studies show that (L1) and (L2) exist in the enol-imine tautomeric form with a strong intramolecular hydrogen bond. NMR studies show that both ligands are found as enol-imine tautomers in CDCl3 solution. In the solid state, the geometry around the copper(II) ion in both (C1) and (C2) is square planar. EPR spectra suggest that the geometry of the complexes is similar to that observed in the solid state by X-ray crystallography. Compound (C2) exhibited the strongest antiplatelet aggregation activity. Conclusion: Schiff base copper(II) complexes, which are attracting increasing interest, could represent a new approach to treat thrombosis by blocking the activity of PolyP with a potential anticoagulant activity and, most importantly, demonstrating no adverse bleeding events.



Materials ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 3790
Author(s):  
Yongzheng Ji ◽  
Tsuyoshi Honma ◽  
Takayuki Komatsu

Sodium super ionic conductor (NASICON)-type Na3Zr2Si2PO12 (NZSP) with the advantages of the high ionic conductivity, stability and safety is one of the most famous solid-state electrolytes. NZSP, however, requires the high sintering temperature about 1200 °C and long sintering time in the conventional solid-state reaction (SSR) method. In this study, the liquid-phase sintering (LPS) method was applied to synthesize NZSP with the use of NaPO3 glass with a low glass transition temperature of 292 °C. The formation of NZSP was confirmed by X-ray diffraction analyses in the samples obtained by the LPS method for the mixture of Na2ZrSi2O7, ZrO2, and NaPO3 glass. The sample sintered at 1000 °C for 10 h exhibited a higher Na+ ion conductivity of 1.81 mS/cm at 100 °C and a lower activation energy of 0.18 eV compared with the samples prepared by the SSR method. It is proposed that a new LPE method is effective for the synthesis of NZSP and the NaPO3 glass has a great contribution to the Na+ diffusion at the grain boundaries.



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