n°28I quarterlyI January 2013 Live from the Labs | 9 w Chemistry Taming Nitrenes R d BY markreynolds Becausenitrenesareimportanttoso chemicals.Theprecedentsarepromising: manychemicalprocesses—likethepro- Bertrand’sstabilizationofcarbenestwo w ductionofammonia,45,000tonsofwhich decadesagoledtoathousand-foldin- Nitrenes are the giant squids and q nitrene structure snow leopards of chemistry—soelu- aremanufacturedeachyear—theyareof crease in carbene-related papers and obtained by X-ray sivethattheyarealmostmythicalinstat- obviousinteresttochemists. patentspublishedeachyear. crystallography, ure.Theyexistonlybrieflyastransitional Tostabilizenitrenes,Bertrandandhis Whiletheapplicationsofnitrenesta- showing nitrogen moleculesduringcertainchemicalreac- teambondedthemwithaphosphorous bilizationareimpossibletopredict,the (blue), phosphorous (red), and carbon tions,andhavesolelybeenobservedat fragment,whichcomputermodelinghad satisfactionofhavingachieveditforthe (black) atoms. extremelylowtemperatures.“Stabilizing predictedwouldserveasanappropriate firsttimeiseasyforBertrandtodescribe. highly-reactivenitrenesatroomtemper- electron“donor.”Thisformedastrong “Itfeelslikebeingthefirstmantowalk atureisliketamingwildanimals,”explains bondandreducedtheintermediate’sin- onthemoon:it’sextremelyexciting.” Joint Research Chemistry Laboratory1 stability.Theresultingphosphinonitrene 01.JointResearchunitbetweenCNRSandthe director GuyBertrand,whoseteamwas retainssomeofthereactivityofnitrenes, universityofCalifornia,Sandiego. 02. dielmannetal.,“ACrystallineSinglet responsibleforarecentbreakthrough.2 butremainsstableinthesolidandliquid Phosphinonitrene:aNitrogenAtomTransferAgent,” “Nitrene has been postulated to be statesatroomtemperatures. Science,2012.337:1526-8. involved inthousandsofreactionsasa Thenewcompoundmightserveasa contactInformatIon: key intermediate that usually reacts nitrogenreagent,abletotransfernitro- Jointresearchchemistrylaboratory,la Jolla. youcannotstopreactionsatthe genatomstoorganicsubstances,thus > guybertrand@ucsd.eduGuy Bertrand further. nitrenestep,”headds. allowingthecreationofanewfamilyof 02 q Halictidae bees (01), soldier beetle Rhagonycha fulva(02), and the butterfly PIPOLL Anthocharis RS u 01 cardamines (03). , INES u N. : Project Surveys Pollinators 03 ©PHOTOS Showcasingthepowerofcitizensci- andbutterflies)—aremoresuitedtoagri- andherbicidestonurtureflowerbloom. ence, SPIPOLL volunteers—numbering culturalandnaturalzones.SPIPOLLalso Thiswouldnotonlybenefitpollinators, 897 to date—contribute photos of in- showsthattherarertheinsects,themore butalsothecroptheyvisit—awin-win sects sighted on flowering plants. The theyfavornaturalareasoverurbanones. solution. long-termgoalistotrackthewaythese The study further contradicts the 01.Conservationdesespèces,restaurationetsuivides populationsevolveovertime.However, ideathat“agriculturalregionsarepoorin populations(MuséumNationald’HistoireNaturelle/ CNRS/universitéParis-VI). thedatahasalreadypinpointedhowpol- insectdiversity,”notesNicolasdeguines, 02.Officepourlesinsectesetleurenvironnement. linatorsarespreadacrossFrance,viaan from the CERSP. Indeed, such areas, 04.SuiviPhotographiquedesInsectesPOLLinisateurs.FlowerofWhereabouts“Theal.,eteguinesd03. indexontheiraffinitywiththreeland-use which cover more than 40% of the Visitors:ContrastingLand-usePreferences types:urban,agricultural,andnatural. Europeancontinent,holdstronginsect- RevealedbyaCountry-WideSurveyBasedone45822.7(9):2012.,PLOS ONEScience,”Citizen Insects of the Hymenoptera order hostingpotentialandshouldbeafocus (including antsandbees)provetobethe forpollinator-friendlypractices,accord- Paris onlypollinatorsactiveonallthreeland ingtotheresearchers.Strategiesinclude contactInformatIon: types. The other orders observed— growing flower strips around fields to cersP, Paris. Coleoptera (beetles), Diptera (flies and providenectarandpollenforpollinators > deguines@mnhn.frNicolas Deguines mosquitoes), and Lepidoptera (moths ororganicfarmingwithfewerpesticides
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