Structural specificity of the initiators for the anionic polymerization of acrylonitrile derived from allyl compounds of molybdenum and tungsten

Abstract

Acta Polymerica 39 (1988) Nr. 12 667 Structural specificity of the initiators for the anionic polymerization of acrylonitrile derived from allyl compounds of molybdenum and tungsten €3. L. ERUSSALIMSKY and L. A. FEDOROVA Academy of Sciences of the USSR, Institute for High Molecular Weight Compounds, Leningrad 199004/IJSSRThe interaction of molybdcnum and tungsten chlorides with ally1 magnesium chloride in the Et,O-THF solvent leads to the formation of (C,H,),Mt. zT1IF complexes, where M t is Mo or W and x is 1 or 2. Moderate heating of toluene solutions of these complexes results in the irreversible loss of THF. Tlic initial complexes and, particularly, t h e products of their interaction with 2,2'-dipyridyl induce a n effective low temperature polymerization of acrylonitrile. The corresponding allyl compounds free from t he THP ligands arc completely passive with respect to this monomer. The causc of this phenomenon is discussed on tlic basis of tlic lH-NMR spectra of tlic investigated active and passive agents. Strukturelle Besonderheiten der auf Allyluerbiindungen des Molybduns oder Wolfrarns basierenden Initiatoren fur die anivnisclie Polynierisat ion des AcrylnitrilsDie Wccliselwirkung von Molybtliinund ~~o l f r a n~c l i l o r i d e n mil Allylmagnesiumchlorid im Losungsmittel Et,O-THF fiihrt zur Bildung von Komplexen der Form (C,II,),Mt . zTHV, wo M t fur itlo bzw. W steht und x = 1 oder 2 ist. MaBige ErwHrmung der Toluenlosungeii dicser Komplcxc bcwirkt ciiie irreversible hbspaltung von THF. Die Ausgangskomplcxe und insbesonderc die Produkte ilirer Wccliselwirkung mit 2,2'-Dipyridyl initiiercn effektiv die Ticftemperaturpolymerisation des Acrylnitrils. Die entspreclicnden voii THF-Iiganden freien Allylvcrbindungen verhalten sich gegcniibcr diescm Monomer vollstiindig passiv. Dic IJrsache diesel. Erscheinung wird an Hand von 1H-NMR-Spektrcn der aktiven und passiven Species diskutiert. CmpyEmypnbie oco6ennocmu uicuyuanzopoc noau~epu3ayuu aqmaouumpuaa ua OCHOBQ aaambmix coedunenuii M O -su6dena u eoab$pa&a B3aHMOAefiCTBHe XJIOPMROB ~o n a 6~e r r a H BOJILapaMa C aJIJIMJIMaI'HMfiXJIOpHAOM B CMeIUaHHOM paCTBOpMTeJIe AM-3THJIOBbTfi B@MP-TI'@ IIpHBORAT K 06pa30BatI€TIO KOMIIJIeKCOB (C,&)4Mt -ZTHF, rne Mt-MO MmEf W M J: -1 MJIH 2. YMepeHHbIB IIpOrpeB TOJIyOJILHbIX PaCTBOpOB 3TMX KOMIIJIeKCOB BLI3bIRaeT He06paTMMOe OTIqeIIneHHe T r @ . BCXOAHbIe KOMIIJIeKCbI M B o c o 6 e a~o c~~ IIpOAyKTLI MX B3aMMOgefiCTBMR C 2,2'-gMIIHpHgHJIOM FIBJIRKITCFI 3$@KTHB-HbIMM HHHqHaTOPaMH HM3KOTeMIIepaTypHOfi IIOJIHMepM3a~MM aKpMJIOHMTpMJIa. Te ECe aJIJIMJIbHbIe CO€!gHHeHMR, CBO-60gHbIe OT Tr@-JIHraHROB, MHePTHbI IIO OTHOLUeHMKI K 3TOMy MOHOMepy. n P H q M H b 1 06HaPyW€!HHOI'O FIBJIeHMR o6cyx-AeHbI Ha OCHOBe IIOJIyYeIIHbIX CIIeKTpOn 'H RMP aKTMBHLIX PI UaCCHBHLIX (POPM YIEa3aHHbIX COe~HHeHMB.

Specificity of initiating systems based on allyl derivatives of group VI-metals in the formation of graft and block copolymers

“…The possible causes for the different behaviour of the n-ally1 and a-ally1 compounds oof Mo and W a s well as their specificity in comparison with TPC have been considered in detail in ref. 6).…”