| This dissertation describes the chemistry of the lanthanide metals and yttrium in oxygen/nitrogen donor atom ligand environments formed by Schiff bases and ϵ-caprolactam derived ligands. Presented first in this dissertation is an examination of a substituted Schiff base ligand, salen′ (N, N′-bis(3,5-di-tert-butylsalicylidene) ethylenediamine) as an alternative ancillary environment to the bis(cyclopentadienyl) ligand set so common in organolanthanide and organoyttrium chemistry. [(salen ′)Y(μ-Cl)(THF)]2 and K(THF)2[(salen ′)2Y] were isolated from reaction of YCl3 in THF with 1 and 2 equivalents) of the K2(salen′), respectively. [(salen′)Y(μ-Cl)(THF)]2 is a viable precursor to organometallic, β-diketone, and amide derivatives.; Presented second in this dissertation is the lanthanide chemistry of ϵ-caprolactam, which is used industrially to produce nylon-6 by ring opening polymerization. Coordination studies of ϵ-caprolactam with a series of lanthanide trichlorides, LnCl3, resulted in the isolation of two types of cationic complexes, [Ln(C6H11NO)6Cl]+2 and [Ln(C 6H11NO)4Cl2]+ that showed a correlation between metal size and the type of complex formed.; Deprotonation of ϵ-caprolactam by the organoyttrium complexes, (C5H4Me)2Y[N(SiMe3)2] and (C5Me5)2Y(C3H5)(THF) led to soluble caprolactamate complexes, [(C5H4Me) 2Y(μ-NC6H10O)]2 and (C5Me 5)2Y(NC6H10O), respectively. Of these two complexes only (C5Me5)2Y(NC6H 10O) was found to be reactive towards CO2, PhNCO and CNCMe 3 at ambient temperatures.; Caprolactamate complexes utilizing the larger lanthanides, (C5Me 5)2Ln(NC6H10O) (Ln = La, Sm) can also be isolated. Both complexes react with CO2 and were also found to catalyze the polymerization of ϵ-caprolactam in the presence of a chain initiator, N-acetylcaprolactam, at 136°C, a temperature that is lower than that commonly used industrially.; Since the lanthanides are active catalysis for the polymerization of polar monomers (e.g. lactones, lactides) and since monomer coordination is likely the first step in metal-based catalysis, knowledge of the preferred orientation of monomer interaction and its binding strength is crucial information. Thus, the final part of this dissertation examines substrate binding. Reaction of [(C5Me5)2Y(μ-Cl)Y(C5Me 5)2Cl] with a variety Lewis bases allowed isolation of several crystallographically characterized adducts, (C5Me5) 2YCl(L). Ligand displacement reactivity monitored by 1H NMR spectroscopy in solution was found to correlate with solid-state bond distances. Both IR and 13C NMR data displayed a general trend with respect to the Y-O distances. |
