Fast atom bombardment mass spectrometry studies of ruthenium (II) polypyridy coordination complexes and of group V Triptycenes and related complexes

In order to investigate the use of Fast Atom Bombardment Mass Spectrometry (FAB-MS) as a tool for structural characterization, two groups of complexes are analyzed. The first group is a set of ruthenium(II) coordination complexes containing bidentate polypyridyl ligands. The positive and negative ion FAB-MS spectra are found to be sufficient to allow for an almost complete characterization of the central metal atom, the ligands and the counter anions contained in the intact complex. An unusual observation of mUltiply charged ions in the positive ion FAB-MS spectra (i.e. [RUL 3 ]2+) is explained to be as a result of the oxidative quenching of the excited state of the doubly charged ion by the matrix, 3-nitrobenzyl alcohol. An analysis of a mixture shows that the technique is a good one for identifying components therein. A group of triptycene and related complexes containing Group V elements is also analyzed by FAB-MS and the results. in terms of relative abundances of fragment ions, are found to be consistent with known metal-carbon bond strengths.

Metal complexes involving pyridoxine and pyridoxamine

Solid complexes of pyridoxine with Mn(II) , Cd(II) and Zn(II) have been isolated, as well as compounds containing Cu(II), Ni(II), Co(III), Cd(II) and Zn(II), and pyridoxamine in various protonated forms. Infrared spectra provide evidence for protonation at the pyridine nitrogen site in the complexes, but not in the neutral vitamins and the complexes of anionic pyridoxamine. Thus the complexed vitamins are in zwitterionic forms, with chelation probably occurring through the phenolate oxygen and either the amino or the hydroxy group at the 4' position.

NMR studies of mixed tetrahaloborates and some related boron trihalide complexes /|nGary John Schrobilgen. -- 260 St. Catharines, Ont. : [s. n.],

Nuclear magnetic resonance spectroscopy has been used to study donor-acceptor complexes of boron trifluoride with several ureas, tetramethylthiourea, tetramethylselenourea, and tetramethylquanidine as well as adducts of tetramethyl- -urea with BF2Cl, BFC1 2 , and BC1 3 - A large number of mixed tetrahaloborate ions, including some of the ternary ones such as BF2CIBr-,have been obtained by ligand exchange reactions and studied by NMR techniques. The bonding in these ions is of the same inherent interest as the bonding in the isoelectronic tetrahalomethanes which have been the subject of many detailed studies and have been involved in a controversy concerning the existence of and the nature of "fluorine hyperconjugation" or C-F P1T- Pn bonding_ Ligand exchange reactions also gave rise to the difluoroboron cation, (TMU)20BF2+o The difluoroboron cation has been observed in solutions of TMU-BF3 , and has been proposed as a possible intermediate for fluorine exchange reactions in BF3 adducts.

Palladium and platinum complexes of vitamin Bâ

Palladium and platinum complexes of pyridoxamine, pyridoxine and pyridoxal have been prepared. The structures of the complexes PtCI2PM.H20, trans-PdC12 (PN)2 and [PLH+ ]2[PtC16] 2- ,H20 have been determined by use of single crystal x-ray studies. The compounds PdC12PH, trans-PdC12 (PN) 2 , cis-PdCI2 (PN)2 and cis PdC12 (PL)2 were also studied by use of carbon-13 nmr spectroscopy. All the complexes have also been characterised by use of infrared spectral studies. In the complexes, PtCI2PM.H20 and PdC12PM, the ligand pyridoxamine is chela ted to the metal through the aminomethyl nitrogen and the phenolate oxygen atoms whereas in the complexes, trans-PdCI2 (PN)2' cis-PdCI2 (PN)2 and cis-PdC12 (PL)2 the vitamin B6 ligands are coordinated to the metal through the pyridine ring nitrogen. The compounds [PLH+ ]2[PtCI6] 2- .H20 and [PMH2] 2+ [PdCI4] 2- .H20have no direct metal-ligand bonding, In all the complexes, the metal maintains a square planar coordination except in [PLH +] 2[PtCI6] 2- ,H20 where the metal is octahedrally coordinated. PH pyridoxamine [PMH ] 2+ = diprotonated pyridoxamine 2 PN = pyridoxine PL pyridoxal PLH+ protonated pyridoxal

Selected topics in fast atom bombardment (FAB) mass spectrometry a)specially designed probe tips and ion generation, b)structures of vitamin B6 schiff base complexes

This thesis can be broken down into two sections. Section one is a study . of the ionization mechanisms and the ion source optimization for Fast Atom Bombardment (FAB) ionization. For this study, several specially designed probe tips were created and tested under various experimental conditions. The aIm of this section is to understand the operating characteristics of a FAB IOn source better. The second section involves the study of several Vitamin B6 Schiff Base complexes using both positive and negative ion FAB MS. This section is an exploration of the usefulness of FAB MS as a structure probe for the metalcoordination complexes of Vitamin B6.

ESI-MS[n] of anticancer pt[iv] organoamido complexes and their interactions with DNA-model compounds /

The general solution behaviour and" the major fragmentation pathways of the anticanceractive PtIV coordination complexes, trans, trans, cis, cis-[PtCIOH{N(pFC6F4) CH2h(pY)2] (1), trans, cis, cis-[Pt(OH)2{N(p-FC6F4)CH2h(Py)2] (2), trans, cis, cis-[Pt(OH)2{N(p-HC6F4)CH2h(Py)2] (3), trans, trans, cis, cis-[PtCIOH{N(pHC6F4) CH2h(Py)2] (4), and trans, trans, cis, cis-[PtOH(OCH3){N(p-HC6F4)CH2h(PY)2] (5) (Py = pyridine) have been deduced by positive-ion tandem-in-time ESI-MS. Overall, the acquired full-scan, positive-ion ESI-MS spectra of 2, 3, and 5 were characterized by the presence of relatively low-intensity [M+Nar and [M+Kt mass spectral peaks, whereas those of 1 and 4 were dominated by extremely intense [M+Hr peaks. Complexes 2 and 3 were also noted to form [2M+Ht and [2M+Nat dilneric cations. The source of Na + and K+ ions is believed to be the sample, the solvent systems used or the transport line carrying the sample solutions into the ES ion source. Further, the fragmentation pathway of all complexes studied was found to be almost identical with concurrent loss of py and H20 molecules, loss of a {N(p-YC6F4)CH2} (Y = F, H) group and/or concomitant release of the latter group and a py ligand being the most conunon. The photochemical degradation behaviour of 1 and 2 was also investigated using either fluorescent or ultraviolet light and some products of that degradation were positively identified. Altogether, light irradiation of solutions of both complexes resulted in cation cationisation, reductive-elimination, ligand-release, ligand-exchange and ligand-addition reactions. Finally, positive- and negative-ion ESI-MSn spectra of 5' -GMP, guanosine, inosine and products of their reactions with 1, 2,3, and 4 were also recorded. On the whole, full-scan ESI-MS spectra of the pure nucleobases revealed the presence of cationic and anionic species that are highly reflective of both their solution ionic composition and their propensity t9 form polymeric clusters. Analyses of mass spectra acquired from their reaction solutions with the aforementioned platinum complexes indicated very slow kinetics. However, all complexes investigated formed, to various degrees, Pt-nucleobase adducts with guanosine and inosine, but not with 5'-GMP. The products included species having coordination numbers of III, IV, V, and VI, among which the first-time· observed, coordinatively saturated, jive-coordinate PtlI-nucleobase complexes were of most interest. The latter complexes are presumably stabilized by 7tback- donation involving the filled d orbitals of the PtII centre and the empty pz· orbital of MeCN. All products, whose peaks appeared inlull-scan ESI-MS spectra, are believed to represent solution species rather than artifacts of gas-phase processes. Finally, negativeion ESI-MSn spectra recorded in reaction solutions of 1 and 4 with guanosine and of the latter complex with inosine revealed the negative-ion-ESI-MS first-time observed, noncovalent, nucleoside-chloride adducts, with the source of chloride anion being complexes 1 and 4 theillselves. In contrast, no such adducts were observed to form with Na25'-GMP or its protonated fonn. Few suggestions are offered for the possible cause(s) behind the absence of such adduct ions.

A qualitative study of inclusion at a residential summer camp

The purpose of this qualitative case study was to understand the inclusion process at a Project Rainbow affiliated camp. Project Rainbow is a non-profit organization which promotes inclusion into children's camps in Ontario. This study was completed in order to provide stakeholders of the camping industry insight on how inclusive techniques can be implemented in residential camps. The researcher observed one camp's inclusion techniques for six days. The researcher observed three campers with disabilities and the camp staff and campers that interacted with them on a daily basis. While the researcher was at the camp, she interviewed nine staff members. The staff members consisted of the camp director, the inclusion coordinator, four camp counsellors, and three inclusion counsellors. An additional interview was conducted after arriving home from camp with the manager from Project Rainbow. The qualitative analysis program NVivo was used to help organize the analyzed data. The researcher found that in attempting to build a culture of inclusion, two important concepts are necessary. First, mutual leadership involved the camp director and Project Rainbow working together as a team to facilitate the inclusion process. Second, power of supportive relationships focused on inclusion being the responsibility of everyone, teamwork, and creating a welcoming environment. Hints at some potentially serious problems related to staff training, teamwork, and attitudes of non-disabled campers pointed to future research and policies which focus on the Ontario and Canadian Camping Associations' role in inclusion, in addition to camp in this study and Project Rainbow.

Kinetic and product studies for the oxidtion of organic sulfides and sulfoxides in the presence of transition metal complexes

Rates and products of the oxidation of diphenyl sulfide, phenyl methyl sulfide, p-chlorophenyl methyl sulfide and diphenyl sulfoxide have been determined. Oxidants included t-Bu02H alone, t-Bu02H plus molybdenum or vanadium catalysts and the molybdenum peroxo complex Mo0(02)2*HMPT. Reactions were chiefly carried out in ethanol at temperatures ranging from 20° to 65°C. Oxidation of diphenyl sulfide by t-Bu02H in absolute ethanol at 65°C followed second-order kinetics with k2 = 5.61 x 10 G M~1s"1, and yielded only diphenyl sulfoxide. The Mo(C0)g-catalyzed reaction gave both the sulfoxide and the sulfone with consecutive third-order kinetics. Rate = k3[Mo][t-Bu02H][Ph2S] + k^[Mo][t-Bu02H][Ph2S0], where log k3 = 12.62 - 18500/RT, and log k^ = 10.73 - 17400/RT. In the absence of diphenyl sulfide, diphenyl sulfoxide did not react with t-Bu02H plus molybdenum catalysts, but was oxidized by t-Bu02H-V0(acac)2. The uncatalyzed oxidation of phenyl methyl sulfide by t-Bu02H in absolute ethanol at 65°C gave a second-order rate constant, k = 3.48 x 10~"5 M^s""1. With added Mo(C0)g, the product was mainly phenyl methyl sulfoxide; Rate = k3[Mo][t-Bu02H][PhSCH3] where log k3 = 22.0 - 44500/RT. Both diphenyl sulfide and diphenyl sulfoxide react readily with the molybdenum peroxy complex, Mo0(02)2'HMPT in absolute ethanol at 35°C, yielding diphenyl sulfone. The observed features are mainly in agreement with the literature on metal ion-catalyzed oxidations of organic compounds by hydroperoxides. These indicate the formation of an active catalyst and the complexation of t-Bu02H with the catalyst. However, the relatively large difference between the activation energies for diphenyl sulfide and phenyl methyl sulfide, and the non-reactivity of diphenyl sulfoxide suggest the involvement of sulfide in the production of an active species.

Nuclear magnetic resonance studies of boron trihalide complexes of 1,1-BIS (dimethylamino) ethylene and related bases

Boron tribalide complexes of 1,1-bis(dimethylamino)ethylene (DME) , t etramethylurea (TMU), tetramethylguanidine (TMG) , and pentamethylguanidine (PMG) and also mixed boron t r ihalide adducts of DME have been investigated by 1H and 19F NMR spectroscopy. Both nitrogen and the C-Q-H carbon of DME are possible donor a toms to boron trihal ides but complexation has been found to occur only at carbon of DME. The initial adduct acts as a Bronsted acid and gives up a proton to free DME in solut ion. A side reaction in the DME-BF, system gives rise to trace amounts of a complex aSSigned as (DME)2BF2+. (DME)2BF2+ is produced in much larger quantities in t he DME-BF3-BC13 and DME-BF,-BBr, systems by reaction of free DME with DME:BF2X (X = Cl, Br). Restricted r otation about the C-N bonds of TMUlBC13 and n1U:BBr3 has been observed at low temperatures. This complements previous work in this system and confirms oxygen donation of TMU to boron trihalides . Restricted rotation at low temperatures also has been observed in DMEboron trihalide systems

Iridium(I) complexes of phenanthroline-derived benzimidazolylidenes : synthetic, structural and catalytic studies

N-heterocyclic carbenes (NHCs) have undergone rapid development in recent years. Due to their strong a-electron donation and structural variability properties, NHCs are becoming a major class of ligands in organometallic chemistry. Compared with the other two types of NHCs (imidazolylidenes and imidazolinylidenes), benzimidazolylidenes have not been well represented. Limited synthetic approaches may impede the development ofbenzimidazolylidenes. This thesis is focused on the synthesis of phenanthroline-derived benzimidazolylidene ligands and their metal complexes. A series of benzimidazolylidene-iridium complexes were synthesized and characterized spectroscopically and crystallographic ally. All of the new complexes showed varying degrees of catalytic activity and enantioselectivity toward transfer hydrogenation and asymmetric hydrogenation. The best results were achieved in hydrogenation of methyl-2-acetamidoacrylate, which afforded (-)-(R)-methyl-2-acetamidopropanoate in 97% yield and 81 % ee.

Examining the inclusion experiences of students with intellectual disabilities : a study focusing on the transition from elementary to secondary school

Transitioning from elementary to secondary school is a major event in adolescents' lives and can be associated with academic, social, and emotional challenges (Shaffer, 2005; Sirsch, 2003). Considerably less research has focused on the transitional experiences of students with intellectual disabilities (lD) as they enter secondary school and the role of educational inclusion in this process (Noland, Cason, & Lincoln, 2007). Conceivably, students with ID who leave inclusive elementary schools, where they have been educated alongside their peers without ID, and who enter segregated secondary educational placements may experience unique social and emotional challenges (Farmer, Pearl, & Van Acker, 1996; Fryxell & Kennedy, 1995; Shaffer, 2005). This study examined the transitional experiences of 6 students with ID and the role of educational inclusion, with a focus on elementary to secondary school transitions from inclusive to segregated settings and vice versa. This study included the collection of multiple sources of data. Semi-structured interviews with 6 caregivers and students with ID were conducted. Students' Individual Education Transitional Plans were discussed in caregivers' interviews to determine how they shaped students' educational inclusion experiences (Ontario Ministry of Education & Training, 1999/2000/2004). Parts ofthe following questionnaires were "qualitized" (Tashakkori & Teddlie, 1998) and administered orally: "Youth Self-Report" (YSR; Achenbach, 2001 c) and "Child Behaviour Checklist Caregivers Form" (CBLC/6-18; Achenbach, 200la). The findings of this study contribute to the literature on educational inclusion by highlighting the positive/negative social and emotional impact of congruent and incongruent transitional experiences of students with ID and the role of educational inclusion.

Deinstitutionalization and community inclusion of individuals with intellectual disabilities in Ontario : a case analysis

In the last few decades, there have been significant changes in the way people with intellectual disabilities (ID) live in many countries around the world. Large isolated institutions have been replaced by community-based housing. This study examined the deinstitutionalization process in Ontario and it's effects on the lives of three individuals with ID. A case analysis approach was used allowing for in depth evaluation of the quality of life of these participants following their discharge with a focus on family involvement, community engagement, and choice making. A discrepancy analysis between the Essential Elements Plan (EEP), constructed when they were entering the community placement, and the current living arrangements was also done. The results of this study suggested that with community living comes improvements in family interactions, community engagement, and decision-making. However, these improvements were found to be minimal. Also, little discrepancy was found between the EEPs and their actual placements.

Asymmetric hydrogenation of alkenes with cationic iridium(I) complexes of 2-phosphino-1-aminoferrocene ligands

Iridium complexes with bidentate P,N ligands represent a class of catalysts that significantly expand the application range of asymmetric hydrogenation. New substrate classes, for which there have previously been no suitable catalysts, can now be efficiently hydrogenated in high conversion and enantioselectivity. These substrates are often of synthetic importance, thus iridium catalysis represents a significant advance in the field of asymmetric catalysis. Planar chiral ferrocenyl aminophosphine ligands in which both heteroatoms were directly bound to the cyclopentadienyl ring were prepared by BF3-activated lithiationsubstitution in the presence of a chiral diamine in 49-59% yield and 75-85% enantiomeric excess. Some of these ligands were recrystallized to enantiomeric purity via ammonium fluoroborate salt formation of the phosphine sulfide. A crystal structure of one of these compounds was obtained and features an intramolecular hydrogen bond between the nitrogen, hydrogen, and sulfur atoms. Neutralization, followed by desulfurization, provided the free ligands in enantiomeric purity. Iridium complexes with these ligands were formed via reaction with [Ir(COD)Clh followed by anion exchange with NaBArF. These complexes were successfully applied in homogeneous hydrogenation of several prochiral substrates, providing products in up to 92% enantiomeric excess. Variation of the dimethyl amino group to a pyrrolidine group had a negative effect on the selectivity of hydrogenation. Variation of the substituents on phosphorus to bulkier ortho-tolyl groups had a positive effect, while variation to the more electron rich dicyclohexyl phosphine had a negative effect on selectivity.

Molybdenum (IV) imido silylamido and hydride complexes : stoichiometric and catalytic reactivity, mechanistic aspects of hydrosilation reactions

This thesis describes the synthesis, structural studies, and stoichiometric and catalytic reactivity of novel Mo(IV) imido silylamide (R'N)Mo(R2)(173_RIN-SiR32-H)(PMe3)n (1: Rl = tBu, Ar', Ar; R2 = Cl; R32 = Me2, MePh, MeCl, Ph2, HPh; n = 2; 2: R' = Ar, R2 = SiH2Ph, n = 1) and hydride complexes (ArN)Mo(H)(R)(PMe3)3 (R = Cl (3), SiH2Ph (4». Compounds of type 1 were generated from (R'N)Mo(PMe3)n(L) (5: R' = tBu, Ar', Ar; L = PMe3, r/- C2H4) and chlorohydrosilanes by the imido/silane coupling approach, recently discovered in our group. The mechanism of the reaction of 5 with HSiCh to give (ArN)MoClz(PMe3)3 (8) was studied by VT NMR, which revealed the intermediacy of (ArN)MCh(172 -ArN=SiHCl)(PMe3)z (9). The imido/silyl coupling methodology was transferred to the reactions of 5 with chlorine-free hydrosilanes. This approach allowed for the isolation of a novel ,B-agostic compound (ArN)Mo(SiHzPh)(173 -NAr-SiHPhH)(PMe3) (10). The latter was found to be active in a variety of hydrosilation processes, including the rare monoaddition of PhSiH3 to benzonitrile. Stoichiometric reactions of 11 with unsaturated compounds appear to proceed via the silanimine intermediate (ArN)M(17z-ArN=SiHPh)(PMe3) (12) and, in the case of olefins and nitriles, give products of Si-C coupling, such as (ArN)Mo(R)(173 -NAr-SiHPh-CH=CHR')(PMe3) (13: R = Et, R' = H; 14: R = H, R' = Ph) and (ArN)Mo(172-NAr-SiHPh-CHR=N)(PMe3) (15). Compound 13 was also subjected to catalysis showing much improved activity in the hydrosilation of carbonyls and alkenes. Hydride complexes 3 and 4 were prepared starting from (ArN)MoCh(PMe3)3 (8). Both hydride species catalyze a diversity of hydrosilation processes that proceed via initial substrate activation but not silane addition. The proposed mechanism is supported by stoichiometric reactions of 3 and 4, kinetic NMR studies, and DFf calculations for the hydrosilation of benzaldehyde and acetone mediated by 4.

Hydrosilylation and hydroboration catalyzed by imido-hydride complexes of molybdenum (IV)

This thesis describes the synthesis, structural studies, stoichiometric and catalytic reactivity of novel Mo(IV) imido hydride complexes (Cp)(ArN)Mo(H)(PMe3) (1) and (Tp )(ArN)Mo(H)(PMe3) (2). Both 1 and 2 catalyze hydrosilylation of a variety of carbonyls. Detailed kinetic and DFT studies found that 1 reacts by an unexpected associative mechanism, which does not involve Si-H addition either to the imido group or the metal. Despite 1 being a d2 complex, its reaction with PhSiH3 proceeds via a a-bond metathesis mechanism giving the silyl derivative (Cp )(ArN)Mo(SiH2Ph)(PMe3). In the presence of BPh3 reaction of 1 with PhSiH3 results in formation of (Cp)(ArN)Mo(SiH2Ph)(H)2 and (Cp)(ArN)Mo(SiH2Ph)2(H), the first examples ofMo(VI) silyl hydrides. AI: 1 : 1 reaction between 2, PhSiD3 and carbonyl substrate established that hydrosilylation is not accompanied by deuterium incorporation into the hydride position of the catalyst, thus ruling out the conventional mechanism based on carbonyl insertion carbonyl. As 2 is nomeactive to both the silane and ketone, the only mechanistic alternative we are left with is that the metal center activates the carbonyl as a Lewis acid. The analogous nonhydride mechanism was observed for the catalysis by (ArN)Mo(H)(CI)(PMe3), (Ph3P)2(I)(O)Re(H)(OSiMe2Ph) and (PPh3CuH)6. Complex 2 also catalyzes hydroboration of carbonyls and nitriles. We report the first case of metal-catalyzed hydroboration of nitriles as well as hydroboration of carbonyls at very mild conditions. Conversion of carbonyl functions can be performed with high selectivities in the presence of nitrile groups. This thesis also reports the first case of the HlH exchange between H2 and Si-H of silanes mediated by Lewis acids such as Mo(IV) , Re(V) , Cu(I) , Zn(II) complexes, B(C6Fs)3 and BPh3.