@article {2494,
	title = {N,O-Chelates of Group 4 Metals: Contrasting the Use of Amidates and Ureates in the Synthesis of Metal Dichlorides},
	journal = {European Journal of Inorganic Chemistry},
	number = {18},
	year = {2009},
	note = {ISI Document Delivery No.: 467LNTimes Cited: 5Cited Reference Count: 69Leitch, David C. Beard, J. David Thomson, Robert K. Wright, Vincent A. Patrick, Brian O. Schafer, Laurel L.},
	month = {Jun},
	pages = {2691-2701},
	type = {Article},
	abstract = {A series of dichloride complexes of titanium and zirconium with amidate and ureate ancillary ligands have been prepared, Three examples of bis(amidate)dichlorotitanium and zirconium complexes were effectively synthesized through salt metathesis with metal tetrachloride as starting materials. Optimum results were achieved using sodium amidate salts formed from sodium bis(trimethylsilyl)amide and neutral amide proligands, while other methods were ineffective. Use of electron-donating ureate ligands in lieu of amidates enables preparation through alternate routes. Protonolysis of Ti(NMe2)(2)Cl-2 and Zr(NMe2)(2)Cl-2(dme) with urea proligands leads to dichlorobis(ureate) complexes in good yield. Using a tethered bis(ureate) ligand eliminates the fluxional behaviour and coordination isomerism observed for both bis(amidate) and bis(ureate) zirconium complexes. ((C) Wiley-VCH Verlag GmbH \& Co. KGaA, 69451 Weinheim, Germany, 2009)},
	keywords = {amidate, BIS(AMIDATE) TITANIUM PRECATALYST, CATALYTIC, Chelates, COORDINATION CHEMISTRY, EARLY, GUANIDINATE LIGANDS, HYDROAMINATION, INTERMOLECULAR HYDROAMINATION, N, O ligands, OLEFIN POLYMERIZATION, SOLUTION DYNAMICS, STRUCTURAL-CHARACTERIZATION, TITANIUM, TRANSITION-METALS, Ureate, ZIEGLER-NATTA POLYMERIZATION, ZIRCONIUM},
	isbn = {1434-1948},
	url = {<Go to ISI>://000267740500015},
	author = {Leitch, D. C. and Beard, J. D. and Thomson, R. K. and Wright, V. A. and Patrick, B. O. and Schafer, L. L.}
}
@article {4807,
	title = {Synthesis, characterization, and reactivity of scandium chloro, alkyl, aryl, and borohydride complexes, Sc(eta(5)-C5H5)R[N(SiMe2CH2P(i)Pr-2)(2)] (R = Cl, Me, Ph, and BH4)},
	journal = {Canadian Journal of Chemistry-Revue Canadienne De Chimie},
	volume = {78},
	number = {7},
	year = {2000},
	note = {ISI Document Delivery No.: 343HDTimes Cited: 16Cited Reference Count: 44},
	month = {Jul},
	pages = {1003-1012},
	type = {Article},
	abstract = {{Reaction of ScCl2(THF)[N((SiMe2CH2PPr2)-Pr-i)(2)] with NaCp(DME) leads to Sc(eta(5)-C5H5)Cl[N((SiMe2CH2PPr2)-Pr-i)(2)] (1). The X-ray crystal structure shows the scandium centre to reside in a square pyramidal environment with the [N((SiMe2CH2PPr2)-Pr-i)(2)] - ligand bound in a pseudo-meridional fashion. The H-1 NMR spectrum is consistent with a C-s symmetric structure in solution. Metathesis of the chloride ligand with RLi (R = Me, Ph, BH4) yields the five-coordinate species Sc(eta(5)-C5H5)R[N((SiMe2CH2PPr2)-Pr-i)(2)]. Phenyl 3 and borohydride 4 are isolated as crystalline solids, while methyl 2 resisted crystallization. 2-4 exhibit H-1 NMR spectra consistent with C-s symmetric solution structures. Sc(eta(5)-C5H5)Ph[N((SiMe2CH2PPr2)-Pr-i)(2)] (3) was characterized in the solid state and found to have a similar geometry to that of the parent chloride. Reaction of Sc(eta(5)-C5H5)Me[N((SiMe2CH2PPr2)-Pr-i)(2)] (2) with NH2R (R = Ph, Bu-t) yields the amides Sc(eta(5)-C5H5)NHPh[N((SiMe2CH2PPr2)-Pr-i)(2)] (5) and Sc(eta(5)-C5H5)(NHBu)-Bu-t- [N((SiMe2CH2PPr2)-Pr-i)(2)] (6) via sigma-bond metathesis routes; these reactions are accompanied by a competing reaction at the scandium-amide bond to produce the protonated ligand, HN((SiMe2CH2PPr2)-Pr-i)(2) 5 and 6 are also produced by salt-elimination from the chloride 1 and LiNHR (R = Ph, Bu-t). Sc(eta(5)-C5H5)(BH4)[N((SiMe2CH2PPr2)-Pr-i)(2)] (4) reacts with PMe3 to produce the putative hydride, Sc(eta(5)-C5H5)H[N((SiMe2CH2PPr2)-Pr-i)(2)] (7); this species was identified in solution. An equilibrium between 4, PMe3, 7, and PMe3,BH3 exists which greatly favors the starting scandium-borohydride. Crystals of Sc(eta(5)-C5H5)Cl[N((SiMe2CH2PPr2)-Pr-i)(2)] (1) are monoclinic},
	keywords = {ALKANE ELIMINATION, BETA-HYDROGEN, borohydride, CHAIN, CHEMISTRY, DERIVATIVES, hydride, LANTHANIDE, PERMETHYLSCANDOCENE, PROPAGATION, RAY CRYSTAL-STRUCTURE, SCANDIUM, sigma-bond metathesis, TETRAHYDROBORATE COMPLEXES, ZIEGLER-NATTA POLYMERIZATION},
	isbn = {0008-4042},
	url = {<Go to ISI>://000088695300009},
	author = {Fryzuk,Michael D. and Giesbrecht, G. R. and Rettig, S. J.}
}
