简介：利用2-羟甲基吡啶(Hhmp)、三乙胺和Mn(CH3COO)2在室温下反应,合成了2D分子基磁性配位聚合物[Mn3Ⅱ(CH3COO)6(H2O)4·(H2O)2]n,其结晶为单斜空间群P21/c.在标题化合物中,Mn2+通过乙酸根离子连接形成线性三核Mn3(CH3COO)6单元;这些单元进一步通过乙酸根离子连接形成1个具有4-连接节点的二维层状44拓扑结构;最后,层与层之间通过氢键连接形成3D超分子网络结构.磁性研究表明,由于缺少反转中心,标题化合物在低温时表现出自旋倾斜反铁磁有序,这在纯乙酸基团构筑的体系中比较少见.

简介：Rareattentionhasbeenpaidtothecomparisonbetweenamonomeranditscorrespondingpolymerintermsoftheoptoelectroniccharacteristics.Inthisarticle,amodelH-shapedmoleculeanditscorrespondingpolymer,bothofwhichexhibitedsimilarpropertiesincludingblueemissionandsolutionprocessing,weredesignedandsynthesized.Optoelectronicpropertiesandvariouskindsofstabilityfeatures,includingthethermostabilities,spectralstabilitiesandamplifiedspontaneousemissioncharacteristicofthemonomerandpolymerwereinvestigated.Ingeneral,thecorrespondingpolymerPHexhibitedsimilaroptoelectronicpropertiesbutdeterioratedstabilitiescomparedwithitsH-shapedmonomerH-1probablyowingtothesimilarchemicalstructurebutthewidermolecularweightdistributionandmetalcatalystresidue.Importantly,monomerH-1displayedacomparableASEthresholdvaluewithitspolymerPH,suggestingthatH-shapedfluorene-basedsmallmoleculesmaybemorepromisingopticalgainmediainsolidstateamplifersandlasers.

简介：Weexperimentallydemonstratedatypeoftunableandswitchableharmonich-shapedpulsegenerationinathulium-dopedfiber(TDF)laserpassivelymodelockedbyusinganultralongnonlinearopticalloopmirror.Thetotalcavitylengthwas~3.03km,thelongesteverbuiltforaTDFlasertoourbestknowledge,whichresultedinanultralargeanomalousdispersionover-200ps~2aroundtheemissionwavelength.Theproducedh-shapedpulsecanoperateeitherinafundamentalorinahigh-orderharmonicmode-locking(HML)statedependingonpumppowerandintra-cavitypolarizationstate(PS).Thepulseduration,nomatteroftheoperationstate,wastunablewithpumppower.However,pulsebreakingandself-organizingoccurred,resultinginhigh-orderHML,whenthepumppowerincreasedaboveathreshold.Atafixedpumppower,theorderofHMLwasswitchablefromonetoanotherbymanipulatingthePS.Switchingfromthe8thuptothe48thorderofHMLwasachievedwithafixedpumppowerof~4.15W.OurresultsrevealedthedetailedevolutionandswitchingcharacteristicsoftheHMLandindividualpulseenvelopewithrespecttoboththepumppowerandPS.Wehavealsodiscussedindetailthemechanismsofboththeh-shapedpulsegenerationandtheswitchingofitsHML.Thiscontributionwouldbehelpfulforfurtherin-depthstudyontheunderlyingdynamicsoflong-durationparticular-envelopepulseswithultralargeanomalousdispersionandultralongroundtriptime.