scholarly journals Effects of Substituents on the Blue Luminescence of Disilane-Linked Donor‒Acceptor‒Donor Triads

Molecules ◽  
2019 ◽  
Vol 24 (3) ◽  
pp. 521 ◽  
Author(s):  
Tsukasa Usuki ◽  
Kenichiro Omoto ◽  
Masaki Shimada ◽  
Yoshinori Yamanoi ◽  
Hidetaka Kasai ◽  
...  
Keyword(s):  
Solid State ◽  
Density Functional ◽  
Photophysical Properties ◽  
Density Functional Theory Calculations ◽  
Molecular Structures ◽  
Optical Measurements ◽  
X Ray Diffraction ◽  
Absolute Quantum Yield ◽  
Donor Acceptor ◽  
Metal Catalyzed

A series of disilane-linked donor‒acceptor‒donor triads (D‒Si‒Si‒A‒Si‒Si‒D) was synthesized to investigate the effects of substituents on the photophysical properties. The triads were prepared by metal-catalyzed diiodosilylation of aryl iodides using a Pd(P(t-Bu)3)2/(i-Pr)2EtN/toluene system that we previously developed. Optical measurements, X-ray diffraction analysis, and density functional theory calculations revealed relationships between the photophysical properties and molecular structures of these triads in solution and in the solid state. The compounds emitted blue to green fluorescence in CH2Cl2 solution and in the solid state. Notably, compound 2 showed fluorescence with an absolute quantum yield of 0.17 in the solid state but showed no fluorescence in CH2Cl2. Our findings confirmed that the substituent adjacent to the disilane moiety affects the conformations and emission efficiencies of compounds in solution and in the solid state.

scholarly journals Structural and Photophysical Properties of 2,1,3-Benzothiadiazole-Based Phosph(III)azane and Its Complexes

Molecules ◽  
2020 ◽  
Vol 25 (10) ◽  
pp. 2428 ◽  
Author(s):  
Radmir Khisamov ◽  
Taisiya Sukhikh ◽  
Denis Bashirov ◽  
Alexey Ryadun ◽  
Sergey Konchenko
Keyword(s):  
Density Functional Theory ◽  
Diffraction Analysis ◽  
Coordination Compounds ◽  
Density Functional ◽  
Photophysical Properties ◽  
Density Functional Theory Calculations ◽  
X Ray Diffraction ◽  
Functional Theory ◽  
X Ray ◽  
Internal Cavities

Here we describe the synthesis of a novel N,N’-bis(2,1,3-benzothiadiazol-4-yl)-1-phenylphosphanediamine (H2L) and its zinc (II) and copper (I) coordination compounds [Zn2L2]·nC7H8 (1·nC7H8), [Zn2(H2L)2Cl4]·nC7H8 (2·nC7H8), and [Cu(H2L)Cl]n·nTHF (3·THF). According to single crystal X-ray diffraction analysis, H2L ligand and its deprotonated species exhibit different coordination modes. An interesting isomerism is observed for the complexes [Zn2(H2L)2Cl4] (2a and 2b) that differ by the arrangement of H2L. Both complexes possess internal cavities capable of incorporating toluene molecules. Upon toluene release, the geometry of 2b changes substantially, while that of 2a changes slightly. Due to the diverse structures, the compounds 1–3 reveal different photophysical properties. These results are discussed based on previously reported studies and DFT (density functional theory) calculations.

scholarly journals Polymerization Isomerism in Co-M (M = Cu, Ag, Au) Carbonyl Clusters: Synthesis, Structures and Computational Investigation

Molecules ◽  
2021 ◽  
Vol 26 (6) ◽  
pp. 1529
Author(s):  
Cristiana Cesari ◽  
Beatrice Berti ◽  
Francesco Calcagno ◽  
Cristina Femoni ◽  
Marco Garavelli ◽  
...  
Keyword(s):  
Solid State ◽  
Density Functional ◽  
Molecular Structures ◽  
Molar Ratio ◽  
X Ray Diffraction ◽  
Functional Theory ◽  
Cluster Chemistry ◽  
Molecular Weights ◽  
Crystallization Conditions

The reaction of [Co(CO)4]− (1) with M(I) compounds (M = Cu, Ag, Au) was reinvestigated unraveling an unprecedented case of polymerization isomerism. Thus, as previously reported, the trinuclear clusters [M{Co(CO)4}2]− (M = Cu, 2; Ag, 3; Au, 4) were obtained by reacting 1 with M(I) in a 2:1 molar ratio. Their molecular structures were corroborated by single-crystal X-ray diffraction (SC-XRD) on isomorphous [NEt4][M{Co(CO)4}2] salts. [NEt4](3)represented the first structural characterization of 3. More interestingly, changing the crystallization conditions of solutions of 3, the hexanuclear cluster [Ag2{Co(CO)4}4]2− (5) was obtained in the solid state instead of 3. Its molecular structure was determined by SC-XRD as Na2(5)·C4H6O2, [PPN]2(5)·C5H12 (PPN = N(PPh3)2]+), [NBu4]2(5) and [NMe4]2(5) salts. 5 may be viewed as a dimer of 3 and, thus, it represents a rare case of polymerization isomerism (that is, two compounds having the same elemental composition but different molecular weights) in cluster chemistry. The phenomenon was further studied in solution by IR and ESI-MS measurements and theoretically investigated by computational methods. Both experimental evidence and density functional theory (DFT) calculations clearly pointed out that the dimerization process occurs in the solid state only in the case of Ag, whereas Cu and Au related species exist only as monomers.

scholarly journals Mechanochemical Syntheses of Isostructural Luminescent Cocrystals of 9-Anthracenecarboxylic Acid with two Dipyridines Coformers

Crystals ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 889
Author(s):  
Torvid Feiler ◽  
Biswajit Bhattacharya ◽  
Adam A. L. Michalchuk ◽  
Vincent Schröder ◽  
Emil List-Kratochvil ◽  
...  
Keyword(s):  
Solid State ◽  
Crystal Engineering ◽  
Density Functional ◽  
Photophysical Properties ◽  
Three Dimensional ◽  
Luminescent Materials ◽  
Primary Role ◽  
X Ray Diffraction ◽  
X Ray ◽  
Interpenetrated Structure

Tuning and controlling the solid-state photophysical properties of organic luminophore are very important to develop next-generation organic luminescent materials. With the aim of discovering new functional luminescent materials, new cocrystals of 9-anthracene carboxylic acid (ACA) were prepared with two different dipyridine coformers: 1,2-bis(4-pyridyl)ethylene and 1,2-bis(4-pyridyl)ethane. The cocrystals were successfully obtained by both mechanochemical approaches and conventional solvent crystallization. The newly obtained crystalline solids were characterized thoroughly using a combination of single crystal X-ray diffraction, powder X-ray diffraction, Fourier-transform infrared spectroscopy, differential thermal analysis, and thermogravimetric analysis. Structural analysis revealed that the cocrystals are isostructural, exhibiting two-fold interpenetrated hydrogen bonded networks. While the O–H···N hydrogen bonds adopts a primary role in the stabilization of the cocrystal phases, the C–H···O hydrogen bonding interactions appear to play a significant role in guiding the three-dimensional assembly. Both π···π and C–H···π interactions assist in stabilizing the interpenetrated structure. The photoluminescence properties of both the starting materials and cocrystals were examined in their solid states. All the cocrystals display tunable photophysical properties as compared to pure ACA. Density functional theory simulations suggest that the modified optical properties result from charge transfers between the ACA and coformer molecules in each case. This study demonstrates the potential of crystal engineering to design solid-state luminescence switching materials through cocrystallization.

scholarly journals Preparation, photoluminescence, semiconductor properties, and theoretical calculations for a novel zinc zero-dimensional structure complex

2019 ◽  
Vol 43 (1-2) ◽  
pp. 58-62 ◽  
Author(s):  
Zhi-Qiang Yi ◽  
Xiao-Niu Fang ◽  
Zi-Yi Cao ◽  
Yao Wei ◽  
Ya-Jing Li ◽  
...  
Keyword(s):  
Solid State ◽  
Density Functional ◽  
Theoretical Calculations ◽  
Density Functional Theory Calculations ◽  
Dimensional Structure ◽  
X Ray Diffraction ◽  
Functional Theory ◽  
Reflectance Measurements ◽  
Metal Charge Transfer ◽  
Semiconductor Properties

The complex [Zn(CH3OH)4(MCA)2] (3-hydroxy-2-methylquinoline-4-carboxylic acid) has been synthesized through hydrothermal reactions and characterized by single-crystal X-ray diffraction. Its solid-state photoluminescence spectrum shows an emission in the blue region, which is assigned to ligand-to-metal charge transfer on the basis of time-dependent density functional theory calculations. Solid-state diffuse reflectance measurements show the existence of a narrow optical band gap of 1.73 eV.

scholarly journals Polymorphs of Rb3ScF6: X-ray and Neutron Diffraction, Solid-State NMR, and Density Functional Theory Calculations Study

2021 ◽  
Vol 60 (8) ◽  
pp. 6016-6026
Author(s):  
Aydar Rakhmatullin ◽  
Maxim S. Molokeev ◽  
Graham King ◽  
Ilya B. Polovov ◽  
Konstantin V. Maksimtsev ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Solid State ◽  
Neutron Diffraction ◽  
Solid State Nmr ◽  
Density Functional ◽  
Density Functional Theory Calculations ◽  
Functional Theory ◽  
X Ray

scholarly journals Ultrafast proton release reaction and primary photochemistry of phycocyanobilin in solution observed with fs-time-resolved mid-IR and UV/Vis spectroscopy

2021 ◽  
Author(s):  
Maximilian Theiß ◽  
Merten Grupe ◽  
Tilman Lamparter ◽  
Maria Andrea Mroginski ◽  
Rolf Diller
Keyword(s):  
Density Functional ◽  
Transient Absorption ◽  
Vibrational Analysis ◽  
Density Functional Theory Calculations ◽  
Chem Phys ◽  
Molecular Structures ◽  
Ir Absorption ◽  
Time Resolved ◽  
Time Constants ◽  
Vis Spectroscopy

AbstractDeactivation processes of photoexcited (λex = 580 nm) phycocyanobilin (PCB) in methanol were investigated by means of UV/Vis and mid-IR femtosecond (fs) transient absorption (TA) as well as static fluorescence spectroscopy, supported by density-functional-theory calculations of three relevant ground state conformers, PCBA, PCBB and PCBC, their relative electronic state energies and normal mode vibrational analysis. UV/Vis fs-TA reveals time constants of 2.0, 18 and 67 ps, describing decay of PCBB*, of PCBA* and thermal re-equilibration of PCBA, PCBB and PCBC, respectively, in line with the model by Dietzek et al. (Chem Phys Lett 515:163, 2011) and predecessors. Significant substantiation and extension of this model is achieved first via mid-IR fs-TA, i.e. identification of molecular structures and their dynamics, with time constants of 2.6, 21 and 40 ps, respectively. Second, transient IR continuum absorption (CA) is observed in the region above 1755 cm−1 (CA1) and between 1550 and 1450 cm−1 (CA2), indicative for the IR absorption of highly polarizable protons in hydrogen bonding networks (X–H…Y). This allows to characterize chromophore protonation/deprotonation processes, associated with the electronic and structural dynamics, on a molecular level. The PCB photocycle is suggested to be closed via a long living (> 1 ns), PCBC-like (i.e. deprotonated), fluorescent species.

scholarly journals Investigation of Solvatomorphism and Its Photophysical Implications for Archetypal Trinuclear Au3(1-Methylimidazolate)3

Molecules ◽  
2021 ◽  
Vol 26 (15) ◽  
pp. 4404
Author(s):  
Shengyang Guan ◽  
David C. Mayer ◽  
Christian Jandl ◽  
Sebastian J. Weishäupl ◽  
Angela Casini ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Solid State ◽  
Density Functional ◽  
Bulk Material ◽  
Variable Temperature ◽  
Active Phase ◽  
Solvent Free ◽  
X Ray Diffraction ◽  
X Ray ◽  
Aurophilic Interactions

A new solvatomorph of [Au3(1-Methylimidazolate)3] (Au3(MeIm)3)—the simplest congener of imidazolate-based Au(I) cyclic trinuclear complexes (CTCs)—has been identified and structurally characterized. Single-crystal X-ray diffraction revealed a dichloromethane solvate exhibiting remarkably short intermolecular Au⋯Au distances (3.2190(7) Å). This goes along with a dimer formation in the solid state, which is not observed in a previously reported solvent-free crystal structure. Hirshfeld analysis, in combination with density functional theory (DFT) calculations, indicates that the dimerization is generally driven by attractive aurophilic interactions, which are commonly associated with the luminescence properties of CTCs. Since Au3(MeIm)3 has previously been reported to be emissive in the solid-state, we conducted a thorough photophysical study combined with phase analysis by means of powder X-ray diffraction (PXRD), to correctly attribute the photophysically active phase of the bulk material. Interestingly, all investigated powder samples accessed via different preparation methods can be assigned to the pristine solvent-free crystal structure, showing no aurophilic interactions. Finally, the observed strong thermochromism of the solid-state material was investigated by means of variable-temperature PXRD, ruling out a significant phase transition being responsible for the drastic change of the emission properties (hypsochromic shift from 710 nm to 510 nm) when lowering the temperature down to 77 K.

scholarly journals CO2 activation through silylimido and silylamido zirconium hydrides supported on N-donor chelating SBA15 surface ligands

2016 ◽  
Vol 52 (12) ◽  
pp. 2577-2580 ◽  
Author(s):  
Farhan Ahmad Pasha ◽  
Anissa Bendjeriou-Sedjerari ◽  
Edy Abou-Hamad ◽  
Kuo-Wei Huang ◽  
Jean-Marie Basset
Keyword(s):  
Density Functional Theory ◽  
Solid State ◽  
Solid State Nmr ◽  
Density Functional ◽  
Density Functional Theory Calculations ◽  
Co2 Activation ◽  
Functional Theory ◽  
Surface Ligands ◽  
Different Types ◽  
Zirconium Hydrides

Density functional theory calculations and 2D 1H–13C HETCOR solid state NMR spectroscopy prove that CO2 can be used to probe, by its own reactivity, different types of N-donor surface ligands on SBA15-supported ZrIV hydrides: [(Si–O–)(Si–N)[Zr]H] and [(Si–NH–)(Si–X–)[Zr]H2] (XO or NH).

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