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1.
ABSTRACTInteractions of cycloheptatriene derivatives, C7H6X, (X?=?NH, PH, AsH, O, S, Se) with the cations H+, CH3+, Cu+, Al+, Li+, Na+, and K+ are studied using B3LYP functional and 6-311++G(d,p) basis set. The calculated gas-phase cation affinities (CA) and cation basicities (CB) for all molecules decrease as H+ > CH3+ > Cu+ > Al+ > Li+ > Na+ > K+. We used the induced aromaticity in the 7-membered ring of C7H6X upon interaction with the cations, M+, as a measure of C7H6X/M+ interaction. Nucleus-independent chemical shift (NICS) and harmonic oscillator model of aromaticity (HOMA) were used as two indices of aromaticity. The highest and lowest induced aromaticities were observed for interactions of H+ and K+, respectively. Also, the aromaticity induced by interaction with a cation in C7H6AsH and C7H6PH was larger than that in C7H6NH and C7H6O. Hence, the aromaticity was considered as a measure of covalency for the C7H6X/M+ interactions showing a rational dependence on both the molecule and cation. The nature of the interactions was also assessed using electron density, charge distribution analysis and NBO calculations. The results of the aromaticity indices, NICS and HOMA, were compared with the electron density and NBO results. 相似文献
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Dr. Shu Min Tan Dr. Carmen C. Mayorga-Martinez Prof. Zdeněk Sofer Prof. Martin Pumera 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(29):6479-6483
Efficient exfoliation and downsizing of Sb2S3 and Bi2S3 layered compounds by using scalable bipolar electrochemistry on their suspensions in aqueous media are here demonstrated. The resulting samples were characterized in detail by transmission electron microscopy, energy-dispersive X-ray spectroscopy, and X-ray photoelectron spectroscopy; their electrochemistry toward hydrogen evolution was also investigated. Hydrogen evolution ability of exfoliated Sb2S3 and Bi2S3 was investigated and compared to the bulk counterparts. 相似文献
4.
Carro María J. Ortiz-Caraballo Carmen 《Journal of Fourier Analysis and Applications》2019,25(1):145-166
Journal of Fourier Analysis and Applications - We prove a weighted estimate for the disc multiplier, acting on radial functions, at the extreme points $$p_{-}=\frac{2n}{n+1}$$ , extending the... 相似文献
5.
The multicomponent Amine-Aldehyde-Dienophile reaction is optimized employing benzyl or 4-methoxybenzylamine. The interest of the transformation consist in the synthesis of polysubstituted cyclohex-2-enylamines. The study of the scope of this AAD process is carried out, as well as the diastereoselective version, employing commercially available chiral benzylic amines and a maleimide with the chiral information at the N-substituent. VCD spectroscopy is a very useful tool for the determination of the absolute configuration of the isolated enantiomerically enriched compounds. 相似文献
6.
Sorin G. Gal 《Results in Mathematics》2014,65(3-4):453-462
By analogy with the probabilistic approach of the classical Bernstein polynomials, in this paper firstly we give the proof for the uniform convergence of the nonlinear max-product Bernstein operator by using the theory of possibility. This new approach, which interprets the max-product Bernstein operator as a possibilistic expectation of a particular fuzzy variable having a possibilistic Bernoulli distribution, does not only offer a good justification for the max-product Bernstein operator, but also allows to extend the method to other discrete max-product Bernstein type operators. 相似文献
7.
Highly Phosphorescent Crystals of Square‐Planar Platinum Complexes with Chiral Organometallic Linkers: Homochiral versus Heterochiral Arrangements,Induced Circular Dichroism,and TD‐DFT Calculations 下载免费PDF全文
Dr. Hugo Sesolis Dr. Julien Dubarle‐Offner Dr. Carmen K. M. Chan Emmanuel Puig Geoffrey Gontard Pierre Winter Prof. Andrew L. Cooksy Prof. Vivian W. W. Yam Dr. Hani Amouri 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(24):8032-8037
A novel class of chiral luminescent square‐planar platinum complexes with a π‐bonded chiral thioquinonoid ligand is described. Remarkably the presence of this chiral organometallic ligand controls the aggregation of this square planar luminophor and imposes a homo‐ or hetero‐chiral arrangement at the supramolecular level, displaying non‐covalent Pt–Pt and π–π interactions. Interestingly these complexes are highly luminescent in the crystalline state and their photophysical properties can be traced to their aggregation in the solid state. A TD‐DFT calculation is obtained to rationalize this unique behavior. 相似文献
8.
Electronic Structure Modulation in an Exceptionally Stable Non‐Heme Nitrosyl Iron(II) Spin‐Crossover Complex 下载免费PDF全文
Lucía Piñeiro‐López Dr. Norma Ortega‐Villar Prof. Dr. M. Carmen Muñoz Dr. Gábor Molnár Dr. Jordi Cirera Prof. Dr. Rafael Moreno‐Esparza Prof. Dr. Víctor M. Ugalde‐Saldívar Dr. Azzedine Bousseksou Prof. Dr. Eliseo Ruiz Prof. Dr. José A. Real 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(36):12741-12751
The highly stable nitrosyl iron(II) mononuclear complex [Fe(bztpen)(NO)](PF6)2 (bztpen=N‐benzyl‐N,N′,N′‐tris(2‐pyridylmethyl)ethylenediamine) displays an S=1/2?S=3/2 spin crossover (SCO) behavior (T1/2=370 K, ΔH=12.48 kJ mol?1, ΔS=33 J K?1 mol?1) stemming from strong magnetic coupling between the NO radical (S=1/2) and thermally interconverted (S=0?S=2) ferrous spin states. The crystal structure of this robust complex has been investigated in the temperature range 120–420 K affording a detailed picture of how the electronic distribution of the t2g–eg orbitals modulates the structure of the {FeNO}7 bond, providing valuable magneto–structural and spectroscopic correlations and DFT analysis. 相似文献
9.
Rose Mary Michell Iwona Blaszczyk‐Lezak Carmen Mijangos Alejandro J. Müller 《Journal of Polymer Science.Polymer Physics》2014,52(18):1179-1194
In this article, a review of recent literature on confined crystallization within nanoporous anodic aluminum oxide (AAO) templates is presented. For almost all infiltrated polymeric materials, crystal orientation within the nanopores is a function of pore diameter. Tc and Tm usually decrease and are a function of pore size. When no pore interconnection remains, the crystallization occur at large supercoolings in heterogeneity free environments. Hence, the nucleation mechanism changes from heterogeneous to surface or homogeneous nucleation. The crystallization kinetics of infiltrated polymers should be close to first order, since in confined environments nucleation is the determining step of the overall crystallization and Avrami indexes (n) of ~1 (or lower in some cases) should be obtained. Examples are provided where these conditions have been met and first order kinetics (n = 1) were measured as opposed to higher orders (n = 3?4) for the same polymer in the bulk. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2014 , 52, 1179–1194 相似文献
10.
Tania Romero‐Morcillo Dr. Maksym Seredyuk Prof. Dr. M. Carmen Muñoz Prof. Dr. Jose A. Real 《Angewandte Chemie (International ed. in English)》2015,54(49):14777-14781
Herein, we report a way to achieve abrupt high‐spin to low‐spin transition with controllable transition temperature and hysteresis width, relying not on solid‐state cooperative interactions, but utilizing coherency between phase and spin transitions in neutral FeII meltable complexes. 相似文献