检索结果-南通市图书馆

spontaneous resolution and absolute chiral induction of 3d-4f heterometal-organic frameworks from achiral precursors

引用

Science China Chemistry 2021年第10期64卷 1698-1702页

作者： Manting Chen Zuochang Chen Huijun Chen Lu Xu Xiangjian Kong Lasheng Long Lansun Zheng Collaborative Innovation Center of Chemistry for Energy Materials State Key Laboratory for Physical Chemistry of Solid SurfacesDepartment of ChemistryCollege of Chemistry and Chemical EngineeringXiamen UniversityXiamen 361005China

The asymmetric assembly and spontaneous resolution of chiral heterometal-organic frameworks from achiral precursors remain a great challenge. Herein, we report the formation and spontaneous resolution of three-dimensional(3 D) chiral 3 d-4 f heterometal-organic frameworks from achiral ligands in the presence of lactic acid enantiomers as chiral inducers. In the absence of a chiral inducer, the reactants randomly generated both enantiopure crystals in equal measure. However, enantiopure lactic acid induced asymmetric resolution to achieve single chiral crystallization. DFT theoretical calculations showed that the absolute chiral resolution of the enantiomers is due to the difference in the interactions between the two enantiomeric Λ/Δ-[Fe L_(3)]^(3-)units and the chiral inducer.

关键词： chirality spontaneous resolution chirality induction heterometal-organic framework achiral precursors

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Rapid spontaneous resolution of lumbar ganglion cysts: A case report

引用

World Journal of Orthopedics 2020年第1期11卷 68-75页

作者： Vito Chiarella Alessandro Ramieri Marco Giugliano Maurizio Domenicucci Department of Neurological and Psychiatric Sapienza University of RomeRome 00185Italy Orthopaedic Division Don Gnocchi FoundationMilan 20148Italy

BACKGROUND To discuss the rare event of spontaneous resolution of a lumbar ganglion cyst,a personal case report and 25 cases culled from the literature were described in detail.We focused on demographic,classification,clinical and radiological findings,treatment,outcome and radiological resolution.CASE SUMMARY A 51-year-old man presented to our observation with complaints of low back and right leg pain.Lumbar magnetic resonance imaging(MRI).showed a L4-L5 ganglion cyst.The patient was referred to medical therapy and bracing.After 4 wk,he showed a complete resolution of pain.The complete spontaneous resolution of the cyst was demonstrated by the followed-up MRI.CONCLUSION spontaneous resolution of lumbar ganglion is very rare and only 26 cases,including ours,were reported in literature.Different degrees of biomechanical impairment seem to play a fundamental role in the pathogenesis.Related symptoms are essentially represented by low back and/or radicular pain,without significant neurological disorders.Anti-inflammatory drugs,light unloading exercises and brace could be recommended to administrated pain and decrease facet loads.Mean time for clinical improvement was 7 mo,while MRI disappearance occurred in an average time of 11 mo.Therefore,surgery should be applied when conservative treatment,prolonged at least 6 mo,fails.

关键词： Lumbar ganglion cyst spontaneous resolution Conservative treatment Radiological disappearance Case report

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

spontaneous resolution of A Cyst of The Septum Pellucidum:a Case Report

Spontaneous Resolution of A Cyst of The Septum Pellucidum:a ...

引用

2011年浙江省神经外科学学术年会

作者： Department of Neurosurgery,2nd Affiliated Hospital,School of Medicine,Zhejiang University,88# Jiefang Road,Hangzhou,Zhejiang,China,310006 Hong,Yuan MD Chen,Sheng MS Guo,Song-Xue MS Zhang,Jian-Min MD,PhD

Septum pellucidum cysts are rare clinical findings.Although their optimal treatment remains controversial,large cysts causing hydrocephalus or neural compression should be treated surgically.However, spontaneous resolution can also occur.Herein,we present a case of a 38-year-old woman suffering from intermittent headache associate with an expanding cyst of the septum pellucidum.No surgical intervention was performed as hydrocephalus was not observed.After 16 months follow up,her symptom disappeared and MRI revealed that the cyst had disappeared.To the best of our knowledge,this is only the third reported case of spontaneous resolution of a septum pellucidum cyst,and suggests that a symptomatic septum pellucidum cyst is not absolute indication of surgical treatment.A conservative approach with close follow up with CT and MRI is strongly recommended unless the cyst causes obvious hydrocephalus or progressive neurological deterioration.

关键词： Septum pellucidum Cyst spontaneous resolution

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

spontaneous resolution of Porous Metal–Organic Frameworks Based on Racemic Precursors

Spontaneous Resolution of Porous Metal–Organic Frameworks B...

引用

中国化学会第十届全国无机化学学术会议

作者： Hua Liu Wen-Qian Zhang Ting-Ting Zheng Ping Liu Yao-Yu Wang College of Chemistry & Materials Science Northwest University

Chirality is an essential feature of life and spans many research fields over pharmaceutics,chemical industry,and biology,etc.The most effective strategy to prepare chiral MOFs is directly using enantiopure ligands as starting materials.spontaneous resolution,however,still remains as a seldom achieved approach and rarely occurs in most reactions.In this work,we choose a typical axially chiral racemic ligand (R,S-HL).Upon the reaction of R,S-HL,Cu(OAc)·HO and N-donor bpy ligand by solution diffusion method,major blue block crystals,a pair of enantiomeric 3D microporous MOFs 1P for R-L and 1M for S-L were obtained.In P-MOF and M-MOF,the R-L or S-L ligands bridge Cu(Ⅱ) ions to generate a left-or right-handed single chiral chain,which are connected through bpy ligands to generate3D chiral frameworks.

关键词： Chirality spontaneous resolution metal–organic frameworks

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

spontaneous resolution and asymmetric synthesis toward octahydrobenzofuran

Spontaneous resolution and asymmetric synthesis toward octah...

引用

中国化学会第六届全国分子手性学术研讨会

作者： Dejie Kong Muhammad Sohail Fu-Xue Chen Department of Applied Chemistry School of Chemical Engineering and the EnvironmentBeijing Institute of Technology

So far,spontaneous resolution has been rarely reported.However,an amazing instance of this phenomenon has been discovered in our laboratory.Enantiomers（S,R）of cyclic γ-alkenyl alcohol（1） could be obtained（optical purity ＞ 99%ee） from the racemic mixture and crystals of both enantiomers could be recognized and separated according to their physical appearance by the naked eye.On the basis of this work,we subsequently explored the asymmetric synthesis of octahydrobenzofuran core structure with three contiguous stereogenic centers and have also established their absolute configurations by single crystal X-ray analysis of 3.In brief,we have successfully developed an efficient and convenient route for the highly diastereoselective synthesis of optically pure octahydrobenzofurans.

关键词： spontaneous resolution mirror images octahydrobenzofuran asymmetric synthesis

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

Seven-year follow-up of spontaneously resolved primary congenital glaucoma:a case report

引用

Annals of Eye Science 2022年第2期7卷 33-37页

作者： Qiaona Ye Yunzhen Wang Jiangang Xu Minbin Yu Yangfan Yang State Key Laboratory of Ophthalmology Zhongshan Ophthalmic CenterSun Yat-sen UniversityGuangzhouChina

Background:spontaneously resolved primary congenital glaucoma is rare and the mechanism remains unknown.Previous literature described the phenomenon of spontaneous resolution of primary congenital glaucoma,with no further reports on follow-up visits and visual development of patients.We report a case of unilateral spontaneously resolved primary congenital glaucoma at a 7-year follow-up visit and describe the differential development of axial length(AL)between affected eye and healthy eye.Case Description:A 6-year-old boy firstly presented at Zhongshan Ophthalmic Center with expanded corneas and ruptures in Descemet’s membranes(Haab’s striae)and apparently thin retinal nerve fiber layer(RNFL)in the left eye(LE),but normal intraocular pressure(IOP)of both eyes without anti-glaucoma medications or surgeries.At 7-year follow-up,the IOPs of bilateral eyes were stable ranging from 8 to 11 mmHg.A cup to disc ratio and the RNFL was stable in the LE at the following visit.The AL increased almost 3 mm in the right eye(RE)but 1.5 mm in the LE.Without anti-glaucoma medications or surgeries,the primary congenital glaucoma was spontaneously resolved.Conclusions:It may figure out the development and influence of the affected eye of the patient,including AL and refraction state with regular ophthalmic examination at periodic follow-up.

关键词： Primary congenital glaucoma spontaneous resolution axial length(AL) case report

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

The synthesis of a new chiral Zn-MOF based on an achiral ligand

The synthesis of a new chiral Zn-MOF based on an achiral lig...

引用

中国化学会第九届全国无机化学学术会议

作者： Na Li Xian-He Bu Department of Chemistry Tianjin Key Lab on Metal and Molecule-based Material ChemistryCollaborative Innovation Center of Chemical Science and Engineering （Tianjin）Nankai University

The design and synthesis of metal-organic frameworks（MOFs）have aroused considerable attention,arising not only from their potential applications in many areas,but also as a result of their chemical and structural diversities[1-2].In recent years,chiral MOFs have attracted attention because their unique applications in asymmetric catalysis,nonlinear optics,chemical sensing and so on[3].To date,lots of chiral MOFs have been reported.However,the rational design and spontaneous resolution of chiral MOFs represent a grand challenge due to its sparse phenomenon and lacks predictability.In this work,a chiral Zn-MOF（1）was synthesized by the use of an achiral ligand 5-（2H-tetrazol-5-yl）isophthalic acid under solvothermal conditions（Fig.1）.1 contains an infinite1D helical chain and its chirality is induced by the symmetry breaking of an achiral ligand.Both enantiomorphic form 1a and 1b are established by single-crystal X-ray diffraction.This is an example of a chiral 3D MOF that is realized by spontaneous resolution.

关键词： Chiral MOF Achiral ligand spontaneous resolution

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

Synthesis,structure,and properties of a novel 1D homochiral MnⅢ（5-Brsalen） coordination polymer with left-handed helical character

Synthesis,structure,and properties of a novel 1D homochiral ...

引用

中国化学会第九届全国无机化学学术会议

作者： Zhaolin Yang Yumeng Wang Fangbin Fan Dapeng Dong Dongping Liu School of Physics and Materials Engineering Dalian Nationalities University

A novel homochiral manganese（Ⅲ）Mn（5-Brsalen）coordination polymer with left-handed helical character by spontaneous resolution on crystallization by using Mn（5-Brsalen）and 4,4-bipyridine has been synthesized.In compound 1,each manganese（Ⅲ）anion is six-coordinate octahedral being bonded to four atoms of 5-Brsalen ligand in an equatorial plane and two nitrogen atoms from a 4,4-bipyridine ligand in axial positions.The structure of compound 1 can be described a supramolecular 2D-like structure which was formed by the intermolecularπ-stacking interactions between the neighboring chains of the aromatic rings of 4,4-bipyridine molecule.

关键词： spontaneous resolution Chirality Crystal structure Electrochemistry

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

A Series of Chiral Lanthanide-Organic Frameworks Built from Achiral Ligands

A Series of Chiral Lanthanide-Organic Frameworks Built from ...

引用

2018年中西部地区无机化学化工学术研讨会

作者： Tao Qin Jie Yang Shunlin Zhang Dun-Ru Zhu College of Chemical Engineering State Key Laboratory of Materials-oriented Chemical Engineering Nanjing Tech University

The molecular chirality is of very importance in both industrial and academic fields including pharmacy,chemistry,and materials science. Over the past two decades,the design and synthesis of chiral metal-organic frameworks (CMOFs) have received extensive attention due to their interesting potential applications in enantioselective separation,asymmetric catalysis,and nonlinear optical materials. Herein a total of eight chiral lanthanide-organic frameworks (CLOFs),L-and D-[LnL(HO)][Ln=Eu (1),Gd (2),Dy (3),and Tb (4),HL=3-nitro-4-(4’-pyridyl)benzoic acid],was hydrothermally synthesized without any chiral auxiliary and characterized by X-ray crystallography.Crystal structural analyses show that L-CLOFs 1-4crystallize in hexagonal P6 space group and are isomorphous,while the enantiomers D-CLOFs1-4 crystallize in hexagonal P6 space group.Each Ln(Ⅲ) is eight-coordinated to six carboxyl Oatoms from six Lligands and two coordinated water molecules in a dodecahedron geometry.An1D neutral helical chain[Ln(CO)] is observed in CLOFs 1-4 as a chiral origin.These helical chains are further interconnected by the directional O-H···N hydrogen bonds between water molecules and pyridyl groups to construct a 3D homochiral network with hex topology (Fig.1).The present LOF is the first chiral 3D hydrogen-bonded hex-net.Solid-state circular dichroism(CD) spectra revealed that CLOFs 1-4 were crystallized through the spontaneous resolution.Furthermore,1 and 4 exhibit characteristic luminescence of Eu(Ⅲ) and Tb(Ⅲ) ions upon excitation.

关键词： LOFs Crystal Structure spontaneous resolution Topology Chiral Framework

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：