主客体化学new

冠醚及其类似物：穴状配体，开链配体和球状配体的主-客体化学Host-guestchemistryofcrownethers(coronands),podands,cryptands,andspherandsHostorreceptor:crownether,etc.…Guestorsubstrate:metalion,etc.…1.冠醚的发现1967，C.J.Pedersen偶然获得,(1987Nobel奖)KMnO4+冠醚溶于苯或氯仿—K+离子掉进了冠醚分子的洞中：由此开创了冠醚类化合物、主-客体化学、分子识别的研究乃至开创了超分子化学。Valinomycin(left)givesastrongandselectivecomplex(right)inwhichaK+ionisincludedinthemacrocycliccavity.2.冠醚类化合物的种类和结构冠醚（crownethers，单环体系）穴状配体（cryptands，多环体系）由J.M.Lehn引入1987Nobel奖开链配体（podands）其他“组合”配体：octopus&lariatethers其他“组合”配体：spherands（Cram引入，1987Nobel奖）(c)cylindricalmacrotricylic(d)sphericalmacrotricylic(a)macrocyclic(b)macrobicyclic3.冠醚类化合物的性质和分子识别冠醚的两亲性(亲脂性和亲水性)和溶解性：不同的溶剂中构象不同配合物在非极性溶剂中更稳定冠醚对碱金属阳离子的配合—球形识别(SphericalRecognition)冠醚环大小的选择效应环过大时能容纳两个阳离子对过渡金属的配合—配位原子的变化—N或S替代O，改变配位行为（HSAB理论）配体的拓扑效应配合物形成速度（动力学）：穴醚（慢）冠醚开链醚（快）配合物稳定性（热力学）：穴醚（稳定）冠醚开链醚（易变）通过改变配位原子的种类，环的大小，拓扑等可以改变冠醚类配体的选择性Forrecognitionoftransitionmetal,lanthanideandactinideions,dependingonthecoordinationfeatureoftheionandthenature,numberanddispositionofbindingsites,aswellastotheirrigidty…刚性大环医学上的应用：抑制病毒、病菌生长，清除重金属，抗肿瘤等。光活性穴状配体+铕或铽冠醚类似物结构和分子识别的拓展1.对质子的“配合”：内部氢键2.四面体识别—NH4+,TetrahedralRecognition3.胺类离子的识别——AmmoniumRelatedSubstrates4.中性分子的识别BindingandRecognitionofNeutralMoleculesHydrogenbonding,-stacking.5.阴离子的识别,RecognitionofAnionicSubstrateRecognitionofhalidesandN3-RecognitionofcarboxylatesN-protonatedformscanbindanions.6.基于bipy的配位体上：肠杆菌素+Fe3+Kf=1052下：肠杆菌素模拟物+Fe3+(6b):Kf=1059Metallacrown,aclassofmetallamacrocycles金属氮杂冠醚See,forexample,B.Kwak,etal.,Inorg.Chem.,1998,37,3599.S.Lin,etal.,J.C.S.,DaltonTrans.,2002,1595.S.X.Liuetal.,Angew.Chem.Int.Ed.,2001,40,1085.J.J.Bodwinetal.,Coord.Chem.Rev.,2001,216-217,489.12-C-4O-CH2-CH2-O12-MC-4O-M-N-OLigandbindingmodeM’m’Xx[A-MC-B]AggregatesofmetallacrownFormolecularrecognitionApplication:MagnetismMolecularrecognition,host-guestchemistrySensorLiquidcrystal……3.1Self-AssemblyofHelicalMetalComplexes:TheHelicatesLineararrayofmetalionsholdtogetherbybridgingpolytopicligandshelicallyarrangedaboutthecentralaxisthroughmetalionsDoubleHelicatesLigandthreads+MetalionsRequirementforligands:EasysynthesisPredictabilityofcoordinationbehaviordesiredmetalbindingdomainsproperdispositionofthesedomainsinspaceflexiblespacerMostusedligands:pyridine-typeligandsOthers:pyrrole-type,…Possibletypesofhelicateformedbyligandsofbidentatemetal-bindingdomainswithfour-coordinateandsixcoordinatemetalions[4+4]helicate:[CuI2(12)2]2+Tetrahedralmetalcentres[6+6]helicate:[CdII2(24)2]4+Octahedralmetalcentresmixed[4+2]helicate:[CuI2(29)2]2+DifferentdoublehelicatesHeterotrinuclearcation[FeAg2(59)2]4+22nmlength27nmlengthnanoarchitecturesTrisilver(I)complexof49PositivecooparativityeffectsfordoublehelicalCu-52complexesLigandscontainingnucleisidesDeoxyribonucleohelicatesDNHPositivelychargedPeripheryhydrogen-bondingbasesInteractionwithorbindingDNA?ChiralityofhelicatesTriplehelicalcation[Co2(41)3]4+Triplehelicalcation[Eu2(63)3]6+9coordinateLn,aromaticstacking[3+3+3]Triplehelicatecation[CuI3(67)3]3+Spacefillingplotofthetriplehelicate150