http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Pomogaev, Vladimir A.,Barachevsky, Valery A.,Tuktarov, Airat R.,Avramov, Pavel V.,Artyukhov, Victor Ya. American Chemical Society 2018 The journal of physical chemistry. A, Molecules, s Vol.122 No.2
<P>The photophysical and isomerization properties of hybrid molecular compounds that consist of photochromic nitro-substituted and halogenated spiropyran derivatives bonded to the surface of the [60]fullerene cage through the pyrrolidine bridge were investigated using various functionals and basis sets of TD-DFT and semiempirical quantum-chemical approaches. The role of <I>n</I>π* states formed by the lone pairs of substituents in changing of the electronic structure and photochromic properties of spiropyran derivatives was evaluated. The S<SUB>ππ</SUB>(spiropyran) → intermediate <I>n</I>π* states → S<SUB>ππ</SUB>(merocyanine) channel for phototransformation of the hybrid compound containing a nitro-substituted spiropyran moiety was established and compared with similar systems of halogenated spiropyrans attached to the [60]fullerene bulk where photoinduced isomerization does not process due to high probability of internal conversion from the excited electronic state localized on the spiropyran fragment to the states of the pyrrolidino[60]fullerene.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/jpcafh/2018/jpcafh.2018.122.issue-2/acs.jpca.7b08374/production/images/medium/jp-2017-08374s_0010.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/jp7b08374'>ACS Electronic Supporting Info</A></P>
Photo-Transformation Trajectories of Nitro-Spiropyran in Hybrid Compounds with [60]Fullerene
Pomogaev, Vladimir A.,Avramov, Pavel V.,Ruud, Kenneth American Chemical Society 2019 JOURNAL OF PHYSICAL CHEMISTRY C - Vol.123 No.30
<P>Photo- and thermo- isomerization trajectories of various conversion pathways between nitro-spiropyran and its <I>trans</I>-<I>trans</I>-<I>cis</I> merocyanine form were produced and the role of <I>n</I>π* states was investigated along the corresponding potential energy surface calculated using the ωB97XD functional and the cc-pVDZ basis set. The nondissociative <I>n</I>π* states on the photoisomerization trajectories can switch from/to the dissociative photoactive ππ* state at two intersections between their energy surfaces. The photochromic properties inherited in hybrid compounds of nitro-spiropyran-containing [60]fullerene are interpreted due to a reversible “dual energy bypass” ππ*↔<I>n</I>π* mechanism in terms of both adiabatic absorption and highly effective nonadiabatic dissipative transitions between the excited states of the photochromic fragment, that prevents energy loss through the [60]fullerene and in this way keeps the photochromic properties intact.</P> [FIG OMISSION]</BR>
Baek, Woohyeon,Gromilov, Sergey A.,Kuklin, Artem V.,Kovaleva, Evgenia A.,Fedorov, Alexandr S.,Sukhikh, Alexander S.,Hanfland, Michael,Pomogaev, Vladimir A.,Melchakova, Iuliia A.,Avramov, Paul V.,Yusen American Chemical Society 2019 NANO LETTERS Vol.19 No.3
<P>For the first time, lonsdaleite-rich impact diamonds from one of the largest Popigai impact crater (Northern Siberia) with a high concentration of structural defects are investigated under hydrostatic compression up to 25 GPa. It is found that, depending on the nature of a sample, the bulk modulus for lonsdaleite experimentally obtained by X-ray diffraction in diamond-anvil cells is systematically lower and equal to 93.3-100.5% of the average values of the bulk moduli of a diamond matrix. Density functional theory calculations reveal possible coexistence of a number of diamond/lonsdaleite and twin diamond biphases. Among the different mutual configurations, separate inclusions of one lonsdaleite (001) plane per four diamond (111) demonstrate the lowest energy per carbon atom, suggesting a favorable formation of single-layer lonsdaleite (001) fragments inserted in the diamond matrix. Calculated formation energies and experimental diamond (311) and lonsdaleite (331) powder X-ray diffraction patterns indicate that all biphases could be formed under high-temperature, high-pressure conditions. Following the equation of states, the bulk modulus of the diamond (111)/lonsdaleite (001) biphase is the largest one among all bulk moduli, including pristine diamond and lonsdaleite.</P> [FIG OMISSION]</BR>
Kovaleva, E.A.,Melchakova, Iuliia,Mikhaleva, N.S.,Tomilin, F.N.,Ovchinnikov, S.G.,Baek, Woohyeon,Pomogaev, V.A.,Avramov, P.,Kuzubov, A.A. Elsevier 2019 The Journal of physics and chemistry of solids Vol.134 No.-
<P><B>Abstract</B></P> <P>Electronic structure and magnetic properties of the family of first-row transition metal dihalides (TM<I>Hal</I> <SUB>2</SUB>, TM = V, Cr, Mn, Fe, Co, Ni; H = Br, I) monolayers were studied by means of density functional theory. Strong electron correlations were taken into account by implementing Hubbard U correction in a simplified scheme proposed by Dudarev et al. (U<SUB>eff</SUB>). U<SUB>eff</SUB> correction essentially affects electronic structure of TM<I>Hal</I> <SUB>2</SUB> widening the band gap and witnessing their highly spin-polarized nature. Two different ligand orientations namely, H and T configurations of monolayers were considered. Unlike others, Fe<I>Hal</I> <SUB>2</SUB> monolayers tend to form H structure when U<SUB>eff</SUB> correction is included.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Atomic and electronic structures of TM<I>Hal</I> <SUB>2</SUB> monolayers were studied by DFT + U method. </LI> <LI> H and T configurations of monolayers were considered. </LI> <LI> Effective Hubbard U correction strongly affects properties of TM<I>Hal</I> <SUB>2</SUB> monolayers. </LI> </UL> </P>