Well-defined calcium initiators for lactide polymerization.
A series of monomeric amide or aryloxide complexes of the form LCaX, where L = CH[CMeNC(6)H(3)-2,6-](2), CH[CMeNC(6)H(4)-2-OMe](2), a bulky tris-pyrazolyl borate, Tp(iPr) or Tp(tBu) or 9-BBN-pz(2) and X = N(SiMe(3))(2) or OC(6)H(3)-2,6-, has been prepared and characterized and investigated in the ring-opening polymerizations of lactide. The compounds (Tp(tBu))CaX in THF are shown to be highly active and stereoselective. The propylene oxide complex (Tp(tBu))Ca(OC(6)H(3)-2,6-).(PO) has been isolated and structurally characterized (single-crystal X-ray) and shown to be inert to the polymerization of PO.
Chisholm
Malcolm H
MH
Department of Chemistry, The Ohio State University, 100 West 18th Avenue, Columbus, Ohio 43210-1185, USA. chisholm@chemistry.ohio-state.edu
Gallucci
Judith C
JC
Phomphrai
Khamphee
K
D002118:Calcium / Q000737:chemistry*; D018360:Crystallography, X-Ray; D019344:Lactic Acid / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D008968:Molecular Conformation; D009942:Organometallic Compounds / Q000138:chemical synthesis / Q000737:chemistry*; D011091:Polyesters / Q000737:chemistry*
D009942:Organometallic Compounds; D011091:Polyesters; D019344:Lactic Acid; C033616:poly(lactide); D002118:Calcium