A new complex, [Ni（L）2]·2（H2O） I （HL = 2-iminomethyl-6-methoxyphenol）, has been synthesized and structurally determined. The crystal belongs to the trigonal system, space group R3- with a = 1.9341 （3）, b ...A new complex, [Ni（L）2]·2（H2O） I （HL = 2-iminomethyl-6-methoxyphenol）, has been synthesized and structurally determined. The crystal belongs to the trigonal system, space group R3- with a = 1.9341 （3）, b = 1.9341 （3）, C = 1.2048（2） nm, V = 3.9029（11） nm^3, Mr = 395.05, Z = 9, Dc = 1.513 g·cm^-3, F（000） = 1854,μ= 1.153 mm^-1 and S = 1.014. Each Ni^Ⅱ atom is four-coordinated by two N and two O atoms from two different L anions to give a slightly distorted square-plane geometry. The complex forms a 3-D network structure through N-H...O and O-H...O hydrogen bonds containing an interesting six-membered water ring.展开更多
A Pd（II）-catalyzed oxidative cyclization of olefinic tosylamides was developed for the preparation of aryl-fused and N-containing six-membered heterocycles. Under optimized conditions the reaction proceeded with hig...A Pd（II）-catalyzed oxidative cyclization of olefinic tosylamides was developed for the preparation of aryl-fused and N-containing six-membered heterocycles. Under optimized conditions the reaction proceeded with high activity and selectivity, with yields of up to 83% being obtained. This procedure provides a facile and efficient route to the aforementioned heterocycles with 2-acetoxy functionality.展开更多
Gutman and Wagner(in the matching energy of a graph, Disc. Appl. Math., 2012) defined the matching energy of a graph and pointed out that its chemical applications go back to the 1970 s. Now the research on matching e...Gutman and Wagner(in the matching energy of a graph, Disc. Appl. Math., 2012) defined the matching energy of a graph and pointed out that its chemical applications go back to the 1970 s. Now the research on matching energy mainly focuses on graphs with pendent vertices and only a few papers reported the progress on matching energy of graphs without pendent vertices. For a random six-membered ring spiro chain, the number of k-matchings and the matching energy are random variables. In this paper, we determine the extremal graphs with respect to the matching energy for random six-membered ring spiro chains which have no pendent vertices.展开更多
The localized molecular orbitals and energy levels for four typical conjugated six-membered ring systems C_6H_6, C_3N_3H_3, B_3N_3H_6, and (B_3O_6)^(3-) as well as a non-aromatic reference molecule N_3Cl_6 have been ...The localized molecular orbitals and energy levels for four typical conjugated six-membered ring systems C_6H_6, C_3N_3H_3, B_3N_3H_6, and (B_3O_6)^(3-) as well as a non-aromatic reference molecule N_3Cl_6 have been calculated by using Edmiston-Ruedenberg energy localization technique under the CNDO/2 approximation in order to investigate the nature of aromaticity or quasi-aromaticity of the six-membered ring systems studied. The contour maps for π-type localized MO's (LMO) have been plotted to illustrate the bonding characteristics of the five ring systems studied. These LMO calculations show that for all the conjugated six-membered ring systems considered there exists local delocalization of π-bonds or three-centered and occasionally four-centered two-electron π-bonds in our terminology, and the cooperative effect among these π-bonds leading to the formation of a closed continuous x-conjugation system around the ring, which is necessary for the creation of aromaticity in the systems studied. We have been able to discuss the properties of these three-centered π-bonds in terms of the constituent atoms and electrons and the relevant orbitals involved.展开更多
The localized molecular orbitals (LMOs) of certain quasi-aromatic organic and inor- ganic molecules with six-membered rings have been calculated by virtue of the ab initio method using STO-3G and 4-31G basis sets as w...The localized molecular orbitals (LMOs) of certain quasi-aromatic organic and inor- ganic molecules with six-membered rings have been calculated by virtue of the ab initio method using STO-3G and 4-31G basis sets as well as the CNDO/2 method. It is shown that there exists extensively-delocalized p-pπ bonding in these quasi-aromatic systems. The localized pictures of the π-type LMOs for the heterocyclic and homocyclic systems from the σ-π localization scheme are discussed. The Generator Orbital approach is utilized to account for the bonding patterns.展开更多
Acid-catalyzed tandem reactions were established by employing a novel class of 2-arylglycerol derivative,5-aryl-1,3-dioxan-5-ol,as versatile 1,3-biselectrophile.In the reactions,5-aryl-1,3-dioxan-5-ol works like atrop...Acid-catalyzed tandem reactions were established by employing a novel class of 2-arylglycerol derivative,5-aryl-1,3-dioxan-5-ol,as versatile 1,3-biselectrophile.In the reactions,5-aryl-1,3-dioxan-5-ol works like atropaldehydes or 2-aryl malondialdehydes,and can react with 2-naphthols andβ-keto amides,allowing the synthesis of 4H-chromenes and 5-aryl-2-pyridinones.High yields,good functional group tolerance,broad substrate scope and simple reaction operation make this protocol attractive.展开更多
An intramolecular organocatalytic enantioselective aza-Michael reaction of carbamates, sulfonamides and acetamides to a,b-unsaturated ketones was developed. This process is promoted by 9-amino-9-deoxy-epi-quinine and ...An intramolecular organocatalytic enantioselective aza-Michael reaction of carbamates, sulfonamides and acetamides to a,b-unsaturated ketones was developed. This process is promoted by 9-amino-9-deoxy-epi-quinine and diphenyl hydrogen phosphate to afford a straightforward and expeditious synthesis of several synthetically useful five-and six-membered heterocycles with excellent enantioselectivity（92%–97.5% ee） and very good yields（up to 99%）.展开更多
In order to maximize performance,birefringent crystals—essential components in laser technology,optical communication,and photonic devices—need to have their optical anisotropy precisely controlled.By combining two...In order to maximize performance,birefringent crystals—essential components in laser technology,optical communication,and photonic devices—need to have their optical anisotropy precisely controlled.By combining twoπ-conjugated organic groups of[C_(5)H_(7)N_(2)]^(+)cation and[C_(4)H_(3)N_(2)O_(3)]^(-)anion in a synergistic manner,this study successfully constructs a novel metal-free molecule(C_(5)H_(7)N_(2))-(C_(4)H_(3)N_(2)O_(3))·H_(2)O using a collaborative design technique based on large anisotropic polar units.According to structural research,the compound’s remarkable birefringence(0.507@546 nm)breaks the record for dual six-membered ring systems.This is due to the highly coplanar alignment that these two planar six-membered ring groups acquire through hydrogen bonding interaction.This study offers a novel design paradigm for creating high-performance,environmentally friendly birefringent materials in addition to empirically verifying the viability of increasing optical anisotropy through the synergistic effects of severalπ-conjugated units.展开更多
[H2N（CH2）3NH312[MoO2（C10H6O2）2] （1） was synthesized by the 2,3-dihydroxynaphthalene in the mixed solvent of CH3OH, CH3CN reaction of （n-Bu4N）4[Mo8O26] with and 1,3-propanediarnine. （C5HllN2）2- [HeN（CH2）3NH...[H2N（CH2）3NH312[MoO2（C10H6O2）2] （1） was synthesized by the 2,3-dihydroxynaphthalene in the mixed solvent of CH3OH, CH3CN reaction of （n-Bu4N）4[Mo8O26] with and 1,3-propanediarnine. （C5HllN2）2- [HeN（CH2）3NH2][MoO2（CloH6O2）2] （2） was obtained by the reaction of Na2MoO4.2H20 with 2,3-dihydroxynaphthalene in the same solvent above. Both of the complexes possess complex anion [Mo（VI）O2（OC10H6O）2]^2- which shows pseudo-octahedrally coordinated fashion, while the counterions are two protonated 1,3-propanediamine in complex 1 and （CsH11N2）^＋ in complex 2. （C5H11N2）＋ is the byproduct of reaction 2, which results from combination of acetonitrile with 1,3-propanediamine. Packing diagrams of the two complexes are also different. There is anti-parallel-aligned-double-meso-bilayer unit in complex 1. However there are four chiral anions arranged in anticlockwise orientation in complex 2.展开更多
1 History of discovery of the low temperature phase barium metaborate （BBO）——an excel-lent new-type ultraviolet radiation frequency-doubling crystalline materialTHE first laser excitation in 1960 with ruby （α-Al...1 History of discovery of the low temperature phase barium metaborate （BBO）——an excel-lent new-type ultraviolet radiation frequency-doubling crystalline materialTHE first laser excitation in 1960 with ruby （α-Al<sub>2</sub>O<sub>3</sub>: Cr） as a laser crystal and the first dou-bling of frequency （347. 15 nm） in 1961 by irradiating quartz crystal （α-SiO<sub>2</sub>） with a 694. 3nm laser beam have laid the basis for the study of laser and nonlinear optical （NLO） crystals,展开更多
基金the Key Laboratory of Non-ferrous Metal Materials and New Processing Technology, Ministry of Education and the State Key Laboratory of Coordination Chemistry
文摘A new complex, [Ni（L）2]·2（H2O） I （HL = 2-iminomethyl-6-methoxyphenol）, has been synthesized and structurally determined. The crystal belongs to the trigonal system, space group R3- with a = 1.9341 （3）, b = 1.9341 （3）, C = 1.2048（2） nm, V = 3.9029（11） nm^3, Mr = 395.05, Z = 9, Dc = 1.513 g·cm^-3, F（000） = 1854,μ= 1.153 mm^-1 and S = 1.014. Each Ni^Ⅱ atom is four-coordinated by two N and two O atoms from two different L anions to give a slightly distorted square-plane geometry. The complex forms a 3-D network structure through N-H...O and O-H...O hydrogen bonds containing an interesting six-membered water ring.
基金Acknowledgement This work was partly supported by the National Natural Science Foundation of China （Nos. 20972095, 21172143, 21232004）, Nippon Chemical Industrial Co., Ltd., the Nature Science Foundation of Ningbo （No. 2012A610086） and Shanghai Jiao Tong University. We thank Prof. Tsuneo Imamoto and Dr. Masashi Sugiya for helpful discussions and the Instrumental Analysis Center of Shanghai Jiao Tong University for HRMS determination.
文摘A Pd（II）-catalyzed oxidative cyclization of olefinic tosylamides was developed for the preparation of aryl-fused and N-containing six-membered heterocycles. Under optimized conditions the reaction proceeded with high activity and selectivity, with yields of up to 83% being obtained. This procedure provides a facile and efficient route to the aforementioned heterocycles with 2-acetoxy functionality.
基金Supported by the the National Natural Science Foundation of China(No.11551003)Scientific research fund of the Science and Technology Program of Guangzhou(No.201510010265)the Qinghai Province Natural Science Foundation(No.2015-ZJ-911)
文摘Gutman and Wagner(in the matching energy of a graph, Disc. Appl. Math., 2012) defined the matching energy of a graph and pointed out that its chemical applications go back to the 1970 s. Now the research on matching energy mainly focuses on graphs with pendent vertices and only a few papers reported the progress on matching energy of graphs without pendent vertices. For a random six-membered ring spiro chain, the number of k-matchings and the matching energy are random variables. In this paper, we determine the extremal graphs with respect to the matching energy for random six-membered ring spiro chains which have no pendent vertices.
文摘The localized molecular orbitals and energy levels for four typical conjugated six-membered ring systems C_6H_6, C_3N_3H_3, B_3N_3H_6, and (B_3O_6)^(3-) as well as a non-aromatic reference molecule N_3Cl_6 have been calculated by using Edmiston-Ruedenberg energy localization technique under the CNDO/2 approximation in order to investigate the nature of aromaticity or quasi-aromaticity of the six-membered ring systems studied. The contour maps for π-type localized MO's (LMO) have been plotted to illustrate the bonding characteristics of the five ring systems studied. These LMO calculations show that for all the conjugated six-membered ring systems considered there exists local delocalization of π-bonds or three-centered and occasionally four-centered two-electron π-bonds in our terminology, and the cooperative effect among these π-bonds leading to the formation of a closed continuous x-conjugation system around the ring, which is necessary for the creation of aromaticity in the systems studied. We have been able to discuss the properties of these three-centered π-bonds in terms of the constituent atoms and electrons and the relevant orbitals involved.
基金Project supported by the National Natural Science Foundation of China the Foundation of the State Key Laboratory of Structural Chemistry of China
文摘The localized molecular orbitals (LMOs) of certain quasi-aromatic organic and inor- ganic molecules with six-membered rings have been calculated by virtue of the ab initio method using STO-3G and 4-31G basis sets as well as the CNDO/2 method. It is shown that there exists extensively-delocalized p-pπ bonding in these quasi-aromatic systems. The localized pictures of the π-type LMOs for the heterocyclic and homocyclic systems from the σ-π localization scheme are discussed. The Generator Orbital approach is utilized to account for the bonding patterns.
基金The National Key Research and Development Project(No.2022YFE0124100)Ordos Key Research and Development Project(No.2022EEDSKJZDZX003)+3 种基金National Natural Science Foundation of China(Nos.21872060,21902054,21761132014,and 22072049)the Open Research Fund(No.2022JYBKF01)of Key Laboratory of Material Chemistry for Energy Conversion and Storage(HUST),Ministry of Education,are acknowledged for the financial supportProgram for HUST Academic Frontier Youth Team(No.2019QYTD06)is also acknowledgedsupported by The Innovation and Talent Recruitment Base of New Energy Chemistry and Device。
文摘Acid-catalyzed tandem reactions were established by employing a novel class of 2-arylglycerol derivative,5-aryl-1,3-dioxan-5-ol,as versatile 1,3-biselectrophile.In the reactions,5-aryl-1,3-dioxan-5-ol works like atropaldehydes or 2-aryl malondialdehydes,and can react with 2-naphthols andβ-keto amides,allowing the synthesis of 4H-chromenes and 5-aryl-2-pyridinones.High yields,good functional group tolerance,broad substrate scope and simple reaction operation make this protocol attractive.
基金financial support from the National Natural Science Foundation of China (No. 21262022)
文摘An intramolecular organocatalytic enantioselective aza-Michael reaction of carbamates, sulfonamides and acetamides to a,b-unsaturated ketones was developed. This process is promoted by 9-amino-9-deoxy-epi-quinine and diphenyl hydrogen phosphate to afford a straightforward and expeditious synthesis of several synthetically useful five-and six-membered heterocycles with excellent enantioselectivity（92%–97.5% ee） and very good yields（up to 99%）.
基金financially supported by the National Natural Science Foundation of China(22101248)the Lvyangjinfeng Talent Program of Yangzhou(YZLYJFJH2021YXBS083)the Qinglan Project of Yangzhou University。
文摘In order to maximize performance,birefringent crystals—essential components in laser technology,optical communication,and photonic devices—need to have their optical anisotropy precisely controlled.By combining twoπ-conjugated organic groups of[C_(5)H_(7)N_(2)]^(+)cation and[C_(4)H_(3)N_(2)O_(3)]^(-)anion in a synergistic manner,this study successfully constructs a novel metal-free molecule(C_(5)H_(7)N_(2))-(C_(4)H_(3)N_(2)O_(3))·H_(2)O using a collaborative design technique based on large anisotropic polar units.According to structural research,the compound’s remarkable birefringence(0.507@546 nm)breaks the record for dual six-membered ring systems.This is due to the highly coplanar alignment that these two planar six-membered ring groups acquire through hydrogen bonding interaction.This study offers a novel design paradigm for creating high-performance,environmentally friendly birefringent materials in addition to empirically verifying the viability of increasing optical anisotropy through the synergistic effects of severalπ-conjugated units.
基金Project supported by the National Natural Science Foundation of China （No. 20271034） and the Beijing Natural Science Foundation （No. 2012005）.
文摘[H2N（CH2）3NH312[MoO2（C10H6O2）2] （1） was synthesized by the 2,3-dihydroxynaphthalene in the mixed solvent of CH3OH, CH3CN reaction of （n-Bu4N）4[Mo8O26] with and 1,3-propanediarnine. （C5HllN2）2- [HeN（CH2）3NH2][MoO2（CloH6O2）2] （2） was obtained by the reaction of Na2MoO4.2H20 with 2,3-dihydroxynaphthalene in the same solvent above. Both of the complexes possess complex anion [Mo（VI）O2（OC10H6O）2]^2- which shows pseudo-octahedrally coordinated fashion, while the counterions are two protonated 1,3-propanediamine in complex 1 and （CsH11N2）^＋ in complex 2. （C5H11N2）＋ is the byproduct of reaction 2, which results from combination of acetonitrile with 1,3-propanediamine. Packing diagrams of the two complexes are also different. There is anti-parallel-aligned-double-meso-bilayer unit in complex 1. However there are four chiral anions arranged in anticlockwise orientation in complex 2.
文摘1 History of discovery of the low temperature phase barium metaborate （BBO）——an excel-lent new-type ultraviolet radiation frequency-doubling crystalline materialTHE first laser excitation in 1960 with ruby （α-Al<sub>2</sub>O<sub>3</sub>: Cr） as a laser crystal and the first dou-bling of frequency （347. 15 nm） in 1961 by irradiating quartz crystal （α-SiO<sub>2</sub>） with a 694. 3nm laser beam have laid the basis for the study of laser and nonlinear optical （NLO） crystals,
