博文
(2022-05-20 16:38:24)
ThereisonereactionbetweenAandB.TheratioofA/Bintheliteratureis1:1.2,thatis,theoreticallyAisexcess.Butafterthereaction,itwasfoundthattheexcessedAisveryhardtoseparatefromtheproductC.SothereactionratiowasmodifiedtoA/B=0.9:1.Bythis,eventhoughtheyieldwaskindofless,pureproductwasobtainedmuchmoreeasily.[阅读全文]
(2022-05-20 16:36:58)
Becarefultousethecorrectamountofreactionreagent.TodayIuseRed-Altoconvertalkynetoalkene.Theconcentrationofitwas65%byweightintoluene.HoweverIuseitaspureonemistakely.Asaresult,theamountofRed-AlIaddedtomyreactionwasnotenoughandthereactiondidnotworkwell.Fortunately,thereactionisjustinsmallscale.Otherwise,thelostwillbeterriblyhuge.[阅读全文]
(2022-05-20 16:35:43)
Diamagneticanisotropyiscommonlyusedtorationalizetheunusualchemicalshiftsofprotonsinacetyleneandinaromaticandantiaromaticcompounds.[阅读全文]
(2022-05-19 16:31:31)
Becarefultousethecorrectamountofreactionreagent.TodayIuseRed-Altoconvertalkynetoalkene.Theconcentrationofitwas65%byweightintoluene.HoweverIuseitaspureonemistakely.Asaresult,theamountofRed-AlIaddedtomyreactionwasnotenoughandthereactiondidnotworkwell.Fortunately,thereactionisjustinsmallscale.Otherwise,thelostwillbeterriblyhuge.[阅读全文]
(2022-05-19 16:30:09)
Incarbohydratechemistry,ananomerisaspecialtypeofepimer.Itisoneoftwostereoisomersofacyclicsaccharidethatdiffersonlyinitsconfigurationatthehemiacetalorhemiketalcarbon,alsocalledtheanomericcarbon.[1]Putsimply,theanomericcarbonisthecarbonylcarbon,forexampleaketoneoraldehydefunctionalgroup,inacarbohydratemolecule.Anomerizationistheprocessofconversionofoneanomertotheother.Anomerizationistheanomericanalo...[阅读全文]
(2022-05-19 16:22:30)
Inchemistryepimersarestereoisomersthatdifferinconfigurationofonlyonestereogeniccenter.Allotherstereocentersinthemolecules,ifany,arethesameineach.Thusepimericmoleculescanbeeitherenantiomersordiastereomersofeachotherdependingonwhethertherearestereocentersinadditiontotheepimericone. Inchemicalnomenclature,oneoftheepimericpairsisgiventheprefixepi-forexampleinquinineandepi-quinine.Whenthepairsareena...[阅读全文]
(2022-05-19 16:16:27)
任何一个实验，做前要仔细把过程读三遍。比如有个四氢铝锂的还原实验，尽管反应温度是室温一小时回流四小时，可加料却在负78度。而我却在室温加料把负78度忽略了。尽管实验还是成功，可还是不应该啊。[阅读全文]
(2022-05-19 16:15:33)
SilicawithGF254hasanflourescentmaterialthatabsorbslightat254nm(hencethe254name)andemitsinthevisiblespectrum.Itworksbecausemanycompoundsalsohavesomeabsorbanceat254nm;thisabsorbanceblocksaportionoftheUVlightfromreachingtheplatecausingreducedfluorescencewherethecompoundislocated,makingdarkspotsthatwesee.GF254板子在紫外灯下可以发出荧光，而一般有紫外吸收的物质在254nm为通用吸收波段，吸收了紫外光，就不能...[阅读全文]
(2022-05-19 16:12:14)
Everyonewantstomakethemostoftheworkday,butthereareseveralbadhabits—likeconstantlycheckingFacebookorneglectingtomaketo-dolists—thatmanypeopleformthatkeepthemfrombeingasproductiveasthey'dlike.Herearesixofthem:CheckingyourpersonalFacebook.Whilesocialmediahasbecomeanintegralpartofcorporatemarketingandcustomerengagement,yourpersonalaccountscanwait.ScrollingthroughInstagramorcatchingupon...[阅读全文]
(2022-05-19 16:11:05)
Cyclohexanonesaredifferentfromcyclohexadienones.socyclohexanonescanbeprotectedby2,2-dimethyl-1,3-propanediolandcatalyticamountofpyridiniump-tosylatebutcyclohexadienonescannot.[阅读全文]
