<p> Dinitrosyliron complexes have gained importance as a result of their biological
and chemical relevance. Their biological significance stems from the roles exhibited by
nitric oxide, including its ability to regulate blood pressure, to act as a biological
messenger and because of its involvement in memory storage. Other functions that these
dinitrosyliron-based complexes have displayed include their ability to transfer molecular
oxygen to alkenes or phosphines, and its use in the polymerization of olefins. One area
not yet extended to iron dinitrosyl complexes involves the synthesis of polymeric
materials containing a conjugated backbone in the polymer. Thus, the next logical
approach was to apply this idea, while investigating their potential to demonstrate unique
properties such as optical, redox, and/or conducting behaviour exemplified by other
inorganic and organometallic polymeric species. Hence, reactions involving
Fe(NO)2(CO)2 and bidentate diphosphine ligands, bis(diphenylphosphino)methane
(DPPM), trans-1,2-bis(diphenylphosphino)ethylene (t-DPPEN), 1,1 '-bis(diphenylphosphino)
ferrocene (FcP2), bis(diphenylphosphino)acetylene (DPPA) and 1,4-
bis(diphenylphosphino)benzene (DPPB) have been investigated. Three types of
compounds arose from these reactions: the monometallic system Fe(DPPM)(N0)2(CO)
9, linear dimetallic molecules of the type Fe2(μ-L)(N0)4(CO)2 (L = PPh2CHzPPh2 10,
PPh2C≡CPPh2 11, PPh2(p -6H4)PPh2 12, PPhzCH=CHPPhz 13, and PPh2((C5H4)2Fe)
PPh2 14), and cyclic dimetallic species of the type Fe2(μ-L)(NO)4 (L = PPh2(p-C6H4)PPh2 15, PPh2CH2PPh2 16, and PPh2C≡CPPh2 17). These systems were isolated
and characterized by the use of NMR and IR spectroscopy. The structures of compounds
10, 11, 16 and 17 were also determined by X-ray crystallography. The linear dimetallic
compounds, 11, 13 and 14, were treated with tetracyanoethylene (TCNE) to afford
compounds of the type Fe2(μ-L)(N0)4(TCNE)2 (L = PPhzC≡CPPh2 18 and PPh2((C5H4)2-
Fe)PPh2 19) and [(TCNE)(NO)2Fe(μ-L)[Fe(NO)2(CO)] (L = PPh2CH=CHPPh2 20).
These TCNE adducts were probed by means of cyclic voltammetry to investigate their
potential redox properties; only compound 18 revealed communication between the two
iron centres. </p>
<p> Dinitrosyldicarbonyliron, Fe(NO)2(CO)2 and other four-coordinate dinitrosyliron
systems have been extensively examined in terms of nucleophilic substitution, including
the effects of both hard and soft bases. These findings prompted us to ask whether
electrophiles attack dinitrosyliron complexes. Hence, Fe(NO)2(CO)2 1, and also the
phosphine complexes Fe(NO)2(CO)(PPh3) 21, and Fe(NO)2(PPh3)2 22, have been treated
with a variety of electrophiles (HCl, SiMe3Cl, Et30^+SbCl6-, trifluoroacetic acid (TFA)
and trifluoromethanesulfonic acid (TFSA)) to probe the nucleophilic character of the iron
centres. Moreover, another approach involved examining the nucleophilic nature of the
iron nitrosyl salts, [PPN^+][Fe(CO)3(NO)], 24 and [N(Bu)4+][Fe(C0)3(NO)], 25. </p> / Thesis / Master of Science (MSc)
| Identifer | oai:union.ndltd.org:mcmaster.ca/oai:macsphere.mcmaster.ca:11375/19258 |
| Date | 08 1900 |
| Creators | Reginato, Nada |
| Contributors | Li, L., McGlinchey, M. J., Chemistry |
| Source Sets | McMaster University |
| Language | English |
| Detected Language | English |
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