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1.
Saqib Kamal Arif I. Inamdar Kuan-Ru Chiou Batjargal Sainbileg Muhammad Usman Jenq-Wei Chen Tzuoo-Tsair Luo Michitoshi Hayashi Chen-Hsiung Hung Wen-Feng Liaw Kuang-Lieh Lu 《Chemistry (Weinheim an der Bergstrasse, Germany)》2022,28(30):e202103905
The dielectric properties of coordination polymers has been a topic of recent interest, but the role of different functional groups on the dielectric properties of these polymers has not yet been fully addressed. Herein, the effects of electron-donating (R=NH2) and electron-withdrawing (R=NO2) groups on the dielectric behavior of such materials were investigated for two thermally stable and guest-free Zn-based coordination polymers, [Zn(L1)(L2)]n ( 1 ) and [Zn(L1)(L3)]n ( 2 ) [L1=2-(2-pyridyl) benzimidazole (Pbim), L2=5-aminoisophthalate (Aip), and L3=5-nitroisophthalate (Nip)]. The results of dielectric studies of 1 revealed that it possesses a high dielectric constant (κ=65.5 at 1 kHz), while compound 2 displayed an even higher dielectric constant (κ=110.3 at 1 kHz). The electron donating and withdrawing effects of the NH2 and NO2 substituents induce changes in the polarity of the polymers, which is due to the inductive effect from the aryl ring for both NO2 and NH2. Theoretical results from density functional theory (DFT) calculations, which also support the experimental findings, show that both compounds have a distinct electronic behavior with diverse wide bandgaps. The significance of the current work is to provide information about the structure-dielectric property relationships. So, this study promises to pave the way for further research on the effects of different functional groups on coordination polymers on their dielectric properties. 相似文献
2.
Hideaki Murasugi Dr. Shohei Kumagai Dr. Hiroaki Iguchi Prof. Dr. Masahiro Yamashita Dr. Shinya Takaishi 《Chemistry (Weinheim an der Bergstrasse, Germany)》2019,25(42):9885-9891
Crystal structures of a series of organic–inorganic hybrid gold iodide perovskites, formulated as A2[AuII2][AuIIII4] [A=methylammonium (MA) ( 1 ) and formamidinium (FA) ( 2 )], A′2[I3]1−x[AuII2]x[AuIIII4] [A′=imidazolium (IMD) ( 3 ), guanidinium (GUA) ( 4 ), dimethylammonium (DMA) ( 5 ), pyridinium (PY) ( 6 ), and piperizinium (PIP) ( 7 )], systematically changed depending on the cation size. In addition, triiodide (I3−) ions were partly incorporated into the AuI2− sites of 3 – 7 , whereas they were not incorporated into those of 1 and 2 . Such a difference comes from the size of the organic cation. Optical absorption spectra showed characteristic intervalence charge-transfer bands from AuI to AuIII species, and the optical band gap increased as the size of the cation became larger. 相似文献
3.
Photochromic indene derivatives, 1-(2-methyl-1-inden-3-yl)-2-(2-methyl-1-benzothien-3-yl)perfluorocyclopentene and 1-(2-methyl-1-inden-3-yl)-2-(2-methyl-1-benzofuran-3-yl)perfluorocyclopentene, were synthesized and their photochromic performance was examined. 相似文献
4.
5.
The recent observation of the cosmic microwave background anisotropy by the WMAP confirmed that the lower multipoles are considerably suppressed. From the standpoint of the cosmic variance, it is nothing but a statistical accident. Alternatively, one can attribute the deficit of fluctuation on the large scale to the cosmic history, which might be explained in the context of the inflationary physics. In this Letter, we show that it is possible to explain the suppressed lower multipoles in the hybrid new inflation model. 相似文献
6.
We reconsider the evolution of strongly degenerate neutrinos in the early universe. Our chief concern is the validity of the entropy conservation after the neutrino annihilation process has frozen out (so that the establishment of chemical equilibrium is not trivial). We argue that the entropy indeed conserves because elastic scattering keeps the neutrino and antineutrino distribution functions in the equilibrium form and the sum of their chemical potential keeps zero even after the neutrino annihilation freeze-out. We also simulate the evolution of the degenerate neutrino spectrum to support the argument. We conclude that the change in the neutrino degeneracy parameter when the relativistic degrees of freedom in the universe decreases is calculated using the entropy conservation and the lepton number conservation without worrying about at what temperature the neutrino annihilation process freezes out. 相似文献
7.
Nanostructure diamond (NSD) film with a hardness as high as 70 GPa and an average surface roughness of 10 nm has been synthesized by the two-step negative substrate bias method combined with post-growth Ar-H2 plasma irradiation. The Ar-H2 plasma irradiation has been confirmed to improve the uniformity of grain size and shape and increase the hardness of the NSD film. 相似文献
8.
Lian-Chun Park Tatsuo Maruyama Noriho Kamiya Masahiro Goto Hiroyuki Kuma Naotaka Hamasaki 《Analytical sciences》2004,20(11):1609-1611
The emergence of drug-resistant hepatitis B virus (HBV) has been reported in patients with prolonged administration of lamivudine, which is a potent drug for the prevention of HBV infection. Lamivudine-resistant HBV has several types of mutations at the YMDD motif of its DNA polymerase. We successfully demonstrated that monitoring the hybridization behavior in nanostructured reverse micelles enables us to detect single nucleotide polymorphisms (SNPs). With the aid of reverse micelles, a model 40-mer oligonucleotide containing a single-base substitution was clearly distinguished from the normal, complementary oligonucleotide. In addition, we extended this technique to a high-throughput analysis. The results obtained with a 96-well micro-plate reader indicated the possibility of SNPs detection toward multiple samples of patients. 相似文献
9.
H. Yonemura S. Moribe K. Hayashi M. Noda H. Tokudome S. Yamada H. Nakamura 《Applied magnetic resonance》2003,23(3-4):289-307
Photoinduced intramolecular electron-transfer reactions in carbazole (Cz)-fullerene (C60) (Cz(8)C60) and phenothiazine (Ph)-C60 (Ph(n)C60 (n=8, 10, 12)) linked compounds have been investigated in benzene and benzonitrile by fluorescence, transient absorption, and time-resolved electron paramagnetic resonance measurements, and by magnetic field effects on the decay rate constants of the photogenerated biradicals. In benzonitrile, photoinduced intramolecular electron transfer from Cz to the singlet excited state of C60 (1C60 *) occurred in Cz(8)C60, but not to the triplet excited state (3C60 *), while the intramolecular electron-transfer to both1C60 * and3C60 * occurred in Ph(n)C60 (n=8, 10, 12). In benzene, on the other hand, no electron transfer to both1C60 * and3C60 * took place in all linked compounds. These results were interpreted in terms of the different Gibbs free energy changes in the two solvents. 相似文献
10.
We shall give a direct proof of the independence result of a Buchholz style-Hydra Game on labeled finite trees. We shall
show that Takeuti-Arai's cut-elimination procedure of and of the iterated inductive definition systems can be directly expressed by the reduction rules of Buchholz's Hydra Game.
As a direct corollary the independence result of the Hydra Game follows.
Received: August 23, 1994 / Revised: July 24, 1995 and May 9, 1996 相似文献