Crystal structures of the Cu(I)/Cu(II) complexes of the pentadentate nitrogen-bonding Schiff-base ligand, $\{$bis-2,6- (1-(2-pyridin-2-ylethylimino)ethyl) pyridine$\}$, (Cu$\sp{\rm I/II}$(py)$\sb2$DAP) $\sp{\rm n+}$, 1, and of the similar ligand, $\{$bis-2,6- (1-(2-imidazol-4yl-ethylimino)ethyl) pyridine$\}$, (Cu$\sp{\rm I}$(imidH)$\sb2$DAP$\sp+$, 2, have been solved as the tetrafluorobrorate salts. The complexes are all pentacoordinate about the copper center. The crystal structure of the tetracoordinate isomer of 1, the Cu(I) complex of $\{$2- (1-(2-imidazol-4yl-ethylimino)ethyl) -6- ((1-tetrahydropyrido (3,4) imidazol)ethyl) pyridine$\}$, (Cu$\sp{\rm I}$(imidH)(imidH)$\sp\prime$DAP) $\sp{\rm n+}$, 4, has also been solved as the tetrafluoroborate salt. The kinetics of the electron self-exchange for the two couples (Cu$\sp{\rm I/II}$(py)$\sb2$DAP) $\sp{\rm n+}$ and (Cu$\sp{\rm I/II}$(imidH)$\sb2$DAP) $\sp{\rm n+}$ has been studied by dynamic NMR, and the kinetics opf electron cross-exchange has also been investigated by reducing (Cu$\sp{\rm II}$(py)$\sb2$DAP) $\sp{2+}$ with the two similar complexes, 2, (Cu$\sp{\rm I}$(imidH)$\sb2$DAP) $\sp+$, and 3, (Cu$\sp{\rm I}$(imidR)$\sb2$DAP) $\sp+$, where R = p-xylyl, and monitoring the reactions with stopped-flow trechniques. These measured rates have been correlated by Marcus theory, and the good agreement suggests an outer-sphere electron transfer mechanism, although the possibility of an inner sphere electron-transfer mechanism has not been ruled out on the basis of ligand substitution kinetics studies and solution phase structural probes for complexes 1 and 2. These electron exchange results are apparently the first to be reported for synthetic Cu(I)/Cu(II) couples in which the coordination number is likely the same in the two oxidation states. (Cu$\sp{\rm I}$(imidH)$\sb2$DAP) $\sp+$, 2, has been previously proposed to form a reversibly-bound dioxygen adduct, which, under removal of the dioxygen, regenerates (Cu$\sp{\rm I}$(imidH)$\sb2$ DAP) $\sp+$. This regeneration step has now been determined to proceed by a route not related to reversible coordination of O$\sb2$, but, instead, by a more complicated redox pathway.

The search for new materials with desirable optical properties has become important in recent years. In particular, a need has emerged for compounds that are candidates for use as long-wavelength (8-12 $\mu$m) infrared window materials. At the present time there is a deficiency of suitable materials which are appropriate for use in the long-wavelength infrared region. This is because there is an inherent conflict (the chemical characteristics that give the best structural and mechanical properties also tend to degrade the optical properties), which needs to be overcome in the search for advanced optical window materials. I have investigated the exploratory synthesis of new mixed-metal chalcogenides, particularly sulfide and selenide compounds, that might display potential for such applications. Our strategy in designing new compounds was to incorporate heavy metals, which display low or intermediate cation coordination, into three-dimensional chalcogenide crystal structures. We felt that the three-dimensional chalcogenide framework would fulfill the structural requirements necessary to retain satisfactory mechanical properties and chemical inertness while allowing the compound to also possess good optical properties. My work entailed the high-temperature (600$\sp\circ$C $\sim$ 1200$\sp\circ$C) solid-state synthesis of new mixed-metal quaternary chalcogenide compounds with a general formula A$\sb{\rm x}$(RE)$\sb{\rm y}$M$\sb{\rm z}$Q$\sb{\rm p}$, where A = Ca or Ba; RE = La-Yb; M = In; and Q = S or Se. Various synthetic techniques, other than conventional high-temperature solid-state methods, have been employed to grow single crystals for physical property measurements; namely vapor transport and molten salt methods. To characterize these new materials, we used a variety of analytical techniques including both single crystal and powder X-ray diffraction techniques, Weissenberg X-ray film techniques, thermal analysis (TGA and DTA), and optical spectroscopy. Preliminary results from DRIFTS (diffuse reflectance infrared fourier transform spectroscopy), single crystal transmittance and UV/VIS reflectance spectroscopy, as well as thermal analysis, suggest that these new compounds may have potential for use in advanced optical devices that are subjected to extreme conditions.

The oxidation kinetics and reaction time mechanisms of some small molecules, thiosulfate, sulfite, and dimethylamine, have been studied in reaction with several transition metal chelates. The rate data were tested for correlation with the Marcus theory for outer sphere electron transfer. The reaction of thiosulfate with a series of (Os (LL)$\sb3$) $\sp{3+}$ complexes (where LL = phen; bpy; 4,7-(Me)$\sb2$phen; 5,6-(Me)$\sb2$phen; and 5-Cl phen) was found to proceed by a simple bimolecular reaction, first order in both (S$\sb2$O$\sb3\sp{2-}$) and (Os (III)). The second order rate constants for these reactions were 1.12 $\times$ 10$\sp2$, 1.30 $\times$ 10$\sp2$, 2.74, 63.0, and 1.47 $\times$ 10$\sp4$ M$\sp{-1}$ s$\sp{-1}$ respectively. The reduction potential for the redox couple S$\sb2$O$\sb3\sp{-/2-}$ was calcuated at 1.30 V. A linear free energy relationship was found; the slope of the plot of log k$\sb{12}$ vs. log K$\sb{\rm eq}$ was 0.48, in excellent agreement with the Marcus LFER prediction of 0.50. This is the first good evidence for an outer sphere electron transfer mechanism for the oxidation of thiosulfate. An analytical method to analyze the polythionates was developed using ion-pair chromatography with conductivity detection and tetraalkylammonium salts for separation. The technique was rapid and sensitive, Tri-, tetra-, and pentathionate were separated along with thiosulfate in less than 15 minutes with detection limits in the sub ppm range for most species. The reaction of sulfite by (Ru (NH$\sb3)\sb4$phen) $\sp{3+}$ has also been studied, along with the reverse reaction of Ru (II) with the sulfite radical generated by pulse radiolysis. The forward reaction exhibited evidence of sulfite radical attack of the phen ring system, the first time this has been observed. The second order rate constant for the forward reaction was 1.00 $\times$ 10$\sp5$ M$\sp{-1}$ s$\sp{-1}$, and the reverse reaction had a rate constant of 1.92 $\times$ 10$\sp8$ M$\sp{-1}$ s$\sp{-1}$. The results did not agree with the Marcus prediction. The other reaction studied was the oxidation of dimethylamine with IrCl$\sb6\sp{2-}$. A range for the rate constant from 300 to 900 M$\sp{-1}$ s$\sp{-1}$ was found. The self exchange rate constant of dimethylamine was calculated as 400 M$\sp{-1}$ s$\sp{-1}$ assuming an outer-sphere mechanism.

The reaction of TlCl$\sb3\cdot$4H$\sb2$O with a methanolic KOH solution of Fe(CO)$\sb5$ is known to produce $\lbrack\rm Et\sb4N\rbrack\sb2\lbrack Tl\sb2Fe\sb4(CO)\sb{16}\rbrack$ which serves as a precursor for several Tl-Fe carbonyl compounds. When a solution of $\lbrack\rm Et\sb4N\rbrack\sb2\lbrack Tl\sb2Fe\sb4(CO)\sb{16}\rbrack$ is allowed to stand in the sunlight for long periods of time, three new thallium-iron carbonyls are also known to result: $\lbrack\rm Et\sb4N\rbrack\sb2\lbrack Tl\sb2Fe\sb6(CO)\sb{24}\rbrack$, $\lbrack\rm Et\sb4N\rbrack\sb4\lbrack Tl\sb4Fe\sb8(CO)\sb{30}\rbrack$ and $\lbrack\rm Et\sb4N\rbrack\sb6\lbrack Tl\sb6Fe\sb{10}(CO)\sb{36}\rbrack$. $\lbrack\rm Et\sb4N\rbrack\sb2\lbrack Tl\sb2Fe\sb6(CO)\sb{24}\rbrack$ may be synthesized by oxidation of $\lbrack\rm Et\sb4N\rbrack\sb2\lbrack Tl\sb2Fe\sb4(CO)\sb{16}\rbrack$ with $\lbrack\rm Cu(MeCN)\sb4\rbrack\lbrack BF\sb4\rbrack$ or by placing a solution of $\lbrack\rm Et\sb4N\rbrack\sb2\lbrack Tl\sb2Fe\sb4(CO)\sb{16}\rbrack$ or $\lbrack\rm Et\sb4N\rbrack\lbrack (tmeda)TlFe\sb2(CO)\sb8\rbrack$ and Fe(CO)$\sb5$ in the sunlight. $\lbrack\rm Et\sb4N\rbrack\sb2\lbrack Tl\sb2Fe\sb4(CO)\sb{16}\rbrack$ also reacts with various bidentate Lewis bases (L) to form adducts of general formula $\lbrack\rm Et\sb4N\rbrack\lbrack (L)TlFe\sb2(CO)\sb8\rbrack$, several of which have been structurally characterized. The indium analogues of $\lbrack\rm Et\sb4N\rbrack\sb2\lbrack Tl\sb2Fe\sb6(CO)\sb{24}\rbrack$ and $\lbrack\rm Et\sb4N\rbrack\lbrack (L)TlFe\sb2(CO)\sb8\rbrack$ have been synthesized by addition of InCl$\sb3$ to K (HFe(CO)$\sb4$), and addition of Lewis bases to $\lbrack\rm Et\sb4N\rbrack\sb2\lbrack In\sb2Fe\sb4(CO)\sb{16}\rbrack$, respectively. The photolysis of a solution of $\lbrack\rm Et\sb4N\rbrack\sb2\lbrack In\sb2Fe\sb4(CO)\sb{16}\rbrack/Fe(CO)\sb5$ also affords $\lbrack\rm Et\sb4N\rbrack\sb2\lbrack In\sb2Fe\sb6(CO)\sb{24}\rbrack$. The reaction of PbCl$\sb2$ with a methanolic KOH/Fe(CO)$\sb5$ solution produces two compounds, depending upon the ratio of starting reagents used: $\lbrack \rm Et\sb4N\rbrack\sb2\lbrack PbFe\sb4(CO)\sb{16}\rbrack$ and $\lbrack \rm Et\sb4N\rbrack\sb2\lbrack Pb\{Fe(CO)\sb4\}\sb3\rbrack$. Similarly, $\lbrack \rm Et\sb4N\rbrack\sb2\lbrack Sn\{Fe(CO)\sb4\}\sb3\rbrack$ is synthesized by reaction of SnCl$\sb2$ with K (HFe(CO)$\sb4\rbrack$. A variable temperature $\sp{13}$C-NMR study of $\lbrack\rm Et\sb4N\rbrack\sb2\lbrack EFe\sb4(CO)\sb{16}\rbrack$, E = Sn, Pb, $\lbrack \rm Et\sb4N\rbrack\sb2\lbrack Pb\{Fe(CO)\sb4\}\sb3\rbrack$ and PbFe$\sb4$(CO)$\sb{16}$ has been undertaken in order to understand the rearrangement processes of the carbonyl ligands occurring in solution. The single crystal X-ray structures of $\lbrack \rm Et\sb4N\rbrack\sb2\lbrack SnFe\sb4(CO)\sb{16}\rbrack$ and $\lbrack \rm Et\sb4N\rbrack\sb2\lbrack E\{Fe(CO)\sb4\}\sb3\rbrack$, E = Sn, Pb, are also reported. The reduction of Ph$\sb2$BiCl with two equivalents of sodium in liquid NH$\sb3$ followed by addition of Fe(CO)$\sb5$ yields two main products, $\lbrack \rm PhBiFe(CO)\sb4\rbrack\sb2$ and (Ph$\sb2$Bi)$\sb2$Fe(CO)$\sb4$, along with traces of Ph$\sb4$Bi$\sb2$. Evidence supports (Ph$\sb2$Bi)$\sb2$Fe(CO)$\sb4$ as an intermediate in the formation of $\lbrack \rm PhBiFe(CO)\sb4\rbrack\sb2$. Treatment of Na$\sb2$Fe(CO)$\sb4$ with one equivalent of Ph$\sb2$BiCl in tetrahydrofuran affords Na$\lbrack\rm Ph\sb2BiFe(CO)\sb4\rbrack$, characterized as the (PPN) $\sp+$ salt. Adding a second equivalent of Ph$\sb2$BiCl to the same reaction produces (Ph$\sb2$Bi)$\sb2$Fe(CO)$\sb4$ or $\lbrack\rm PhBiFe(CO)\sb4\rbrack\sb2$, depending on the reaction time. (PhBiFe(CO)$\sb4\rbrack\sb2$ is also obtained in poor yield from the reaction of PhBiBr$\sb2$ and Na$\sb2$Fe(CO)$\sb4{\cdot}3/2$ dioxane in THF. (PhBiFe(CO)$\sb4\rbrack\sb2$, (PPN) (Ph$\sb2$BiFe(CO)$\sb4\rbrack$ and (Ph$\sb2$Bi)$\sb2$Fe(CO)$\sb4$ have been characterized by single crystal X-ray diffraction.

The direct reaction of elemental fluorine with diamonds, YBa$\sb2$Cu$\sb3$O$\sb{\rm 7-x}$, and some unique organic materials has been studied. It has been found that diamonds (powder, slabs, and CVD films) can be directly fluorinated to a small extent using elemental fluorine under various reaction conditions. The reaction appears to proceed by fluorine attacking the diamond's more labile surface features such as the hydroxyl group. While the diamond surface is reactive to some extent, it is difficult to fully fluorinate this surface with elemental fluorine. Plasma fluorination seems to lead to the formation of CF terminal bonds on the diamond surface while high temperature direct fluorination leads to the formation of CF$\sb2$ and CF$\sb3$ terminal bonds. In oxidation resistance studies, the CF$\sb2$ and CF$\sb3$ terminal bonds lead to a more stable product than do the CF bonds. The direct fluorination of the high temperature superconductor, YBa$\sb2$Cu$\sb3$O$\sb{\rm 7-x}$, leads primarily to the formation of a non-superconducting phase. This phase encapsulates the superconducting phase. Thus, there is no significant change in the fluorinated material's onset of critical temperature, but there is a significant decrease in the degree of magnetic shielding for the material as the amount of fluorination is increased. Initial attempts at synthesizing nitrofluorosuperconductors are presented. We have successfully used direct fluorination techniques to yield improved properties for Velcro (made principally of polypropylene) and have had some success at fluorinating indan and PVC. The fluoro-Velcro shows enhanced lint repellent properties while maintaining its suppleness and other desirable properties. Perfluoroperhydroindan, a potential fluoroblood, has been prepared in small quantities using this novel treatment. PVC has been modestly fluorinated with the potential of carrying the fluorination to completion and should yield a superior product. The use of cubic zirconia, an inexpensive diamond simulant, as high pressure/high temperature transmitting windows in the diamond anvil optical cell has been shown to be promising. Pressures nearing 20 kbars can be obtained in the cell using cubic zirconia anvils. The optical properties of cubic zirconia open up a region of the mid-IR that has been inaccessible with previous windows at these pressures. An FT-IR study of the high pressure effects on Fe(CO)$\sb6$($\mu$-CO)$\sb2$($\mu$-CH$\sb2$) is presented as proof. (Abstract shortened with permission of author.)

Zinc(II), copper(II), and copper(I) complexes of the pentadentate ligand, ((5-MeimidH)$\sb2$DAP) were prepared and studied as their (BF$\sb4$)$\sp-$ salts. The divalent compounds, (M$\sp{\rm II}$((5-MeimidH)$\sb2$DAP)) (BF$\sb4$)$\sb2$ (M = Zn, Cu), were found to have intermediate geometries between idealized trigonal bipyramidal and square pyramidal structures by x-ray crystallography. It is assumed that (Cu$\sp{\rm I}$((5-MeimidH)$\sb2$DAP)) (BF$\sb4$) is also pentacoordinate as is its parent compound, (Cu$\sp{\rm I}$((imidH)$\sb2$DAP)) (BF$\sb4$). In addition to the x-ray structures, the new compounds have been fully characterized, where appropriate, by a battery of techniques for both the solid and solution states. These studies all suggest that the pentacoordinate structures of the solid state are also retained in solution. Variable-temperature proton NMR studies in non-aqueous solvents were used to extensively probe the intramolecular conformational dynamics of (M((5-MeimidH)$\sb2$DAP)) $\sp{\rm n+}$ (M = Zn(II), Cu(I)) and two related pentacoordinate systems ((M((imidH)$\sb2$DAP)) $\sp{\rm n+}$ and (M((py)$\sb2$DAP)) $\sp{\rm {n+}}$). Computer simulation of the temperature-dependent methylene proton regions were used to observe $\lambda$ and $\delta$ chelate ring conformations. Coalesence rate constants were obtained in four of the six cases. The electron self-exchange rate of the (Cu((5-MeimidH)$\sb2$DAP)) $\sp{+/2+}$ couple was measured in CD$\sb3$CN, as a function of temperature, by dynamic NMR line-broadening techniques. Under controlled conditions ($\mu$ = 25 mM), the observed rate constant ranged from 0.9($\pm$0.1) $\times$ 10$\sp4$ M$\sp{-1}$ s$\sp{-1}$ (243 K) to 3.9($\pm$0.4) $\times$ 10$\sp4$ M$\sp{-1}$ s$\sp{-1}$ (293 K) with activation parameters of $\Delta$H$\sp\ddagger$ = 12.5 kJ mol$\sp{-1}$ and $\Delta$S$\sp\ddagger$ = $-$116 J mol$\sp{-1}$ K$\sp{-1}$. The present electron self-exchange rate constant, together with those for two related Cu(I/II) couples ((Cu((imidH)$\sb2$DAP)) $\sp{+/2+}$ and (Cu((py)$\sb2$DAP)) $\sp{+/2+}$) indicate a possible relationship between intramolecular dynamics of the Cu(I) species and the electron self-exchange rates of the Cu(I/II) couples. Finally, the reactivity of (Cu$\sp{\rm I}$((5-MeimidH)$\sb2$DAP)) $\sp+$ towards O$\sb2$ was investigated and found to be something other than a reversible process. Although an initial uptake stoichiometry of 2Cu:O$\sb2$ was obtained by manometry, a Toepler pump experiment showed that regeneration of Cu(I) proceeded without significant release of O$\sb2$.

The objective of this research is the development of an environmentally-benign process for the synthesis and fabrication of alumina-based ceramic precursors and advanced ceramic materials. Carboxylate-alumoxanes, [Al(O)x(OH) y(O2CR)z]n, were synthesized by the reaction of boehmite, [Al(O)(OH)]n, with acetic acid (HO2 CCH3), methoxyacetic acid (HO2CCH2OCH 3), methoxyethoxyacetic acid (HO2CCH2OCH 2CH2OCH3) and methoxyethoxyethoxyacetic acid [HO 2CCH2(OCH2CH2)2OCH 3]. Carboxylate-alumoxanes can be considered inorganic-organic hybrid materials consisting of an aluminum-oxygen backbone with carboxylate substituents. These are infinitely stable at ambient conditions in solid and solution. In addition, they show no propensity to segregation or polymerization and are readily processed in aqueous or hydrocarbon medium. Upon thermolysis the carboxylate-alumoxanes are converted to alumina. The physical and spectroscopic properties of the carboxylate-alumoxanes have been determined. The potential environmental impact of the new alumoxane methodology will be discussed. Carboxylate-alumoxanes are reacted with metal acetylacetonate complexes, M(acac)n, to form metal-doped nanoparticles and aluminum acetylacetonate via a transmetalation reaction. This allows the facile formation of highly crystalline materials such as calcium hexaluminate (CaAl12O 19, hibonite) and lanthanum hexaluminate. The formation of highly phase pure materials is proposed to be due to the presence of atomic scale mixing within the metal doped alumina nanoparticle structure of the carboxylate-alumoxane. The potential of the carboxylate alumoxanes as interlayer coatings in ceramic matrix composites (CMCs) was investigated. Sapphire, SiC, carbon, and KevlarRTM fibers and carbon/KevlarRTM fabric have been dip-coated by aqueous and CHCl3 solutions of carboxylate-alumoxane nanoparticles and fired to 1400°C to form uniform alumina and aluminate coatings. Optimum solvent, dip/dry, and firing sequences were determined for the formation of crack-free coatings. Coatings produced were stable to thermal cycling under air at temperatures of 1400°C. The ability of the carboxylate-alumoxanes to provide crack infiltration and repair of damaged coatings is demonstrated.

The reaction between triphenyl bismuth and salicylic acid in refluxing toluene proceeds via an acid hydrolysis pathway to produce a yellow complex analyzing as bismuth (III) salicylate---[Bi(Hsal)3]n---in quantitative yield. The composition of the complex is critically affected by the ratio of bismuth to salicylic acid that is employed in the reaction mixture. The material produced from a 1:3 ratio of bismuth to salicylic acid being essentially insoluble, while the product of a 1:20 ratio of bismuth:salicylic acid is soluble in a wide range of solvents including hot toluene. Bismuth (III) salicylate is a useful synthon for the formation of heterobimetallic coordination complexes. The material reacts readily with the transition metal alkoxides Ti(OiPr)4, Nb(OEt)5 and Ta(OEt)5 to produce bimetallic compounds by an alcohol exchange pathway. The reactivity of the bismuth salicylate is mediated by the acidity of the phenolic oxygen on the salicylate ligand. The composition of the complexes produced in this manner are affected by the stoichiometry of the reagents, the concentration of water in the reaction mixture, the solvent polarity and the pH of the system and, most importantly, the identity of the transition metal species. Heterobimetallic complexes can also be produced by direct Lewis acid-base adduct formation between bismuth (III) salicylate and metal complexes. The complexes produced in this manner have lower nuclearity than the compounds derived from the alkoxide-based routes, but better control over the ultimate stoichiometry of the system is obtained. The heterobimetallic complexes produced through both reaction pathways smoothly decompose to produce crystalline binary oxide materials. In general, the conditions required to achieve decomposition and crystallization of the molecular precursors are significantly reduced compared to traditional solid-state syntheses. The properties of the oxides produced from the molecular precursors including crystallinity, morphology and phases present are strongly influenced by the conditions of decomposition.

Single wall carbon nanotubes (SWNTs) are novel materials with unique chemical and physical properties: they are the strongest fiber ever made; they have outstanding thermal conductivity and unique one dimensional electrical conductivity; their weight is light and their individual size is only 0.4 to several nm in diameter. A wide range of applications of SWNTs were proposed including high performance polymer composites, field emitter for flat panel display, energy storage, molecular electronics and biomedical applications, etc. Functionalization of SWNTs has been an important pathway to utilize SWNTs for many of these applications. This thesis studies the fluorination of SWNTs, electrochemical properties of fluorinated SWNTs as a cathode material in lithium batteries and oxidative properties and thermal stabilities of fluorinated SWNTs in a binary metal compound matrix. This thesis also studies functionalization of SWNTs through a free radical addition process, in which radicals were from the thermal decomposition of organic diacyl peroxides including lauryl peroxide, benzoyl peroxide, succinic acid peroxide and glutaric peroxide. Functionalized SWNTs prepared from this method have improved solubility in various common organic solvents. They are characterized with a variety of techniques including Raman, FTIR, TGA/MS, TEM and solid state 13C NMR. A parallel study on C60 fullerene is also included. The succinic acid peroxide is of particular interest for functionalization because it can attach ethylenecarboxyl groups (--CH2CH 2COOH) to the sidewall of SWNTs. The sidewall acid groups, after reacting with thionyl chloride and diamines, are converted to terminal amine groups, which can form covalent bonds with epoxy polymers to prepare SWNT reinforced epoxy polymer composites. Mechanical tests show that the tensile strength, elongation and storage modulus of epoxy are greatly improved (25∼30%) with 1 weight percent of SWNTs addition.

Thin films have been prepared via the solution-phase-self-assembly of organometallic chalcogen-containing cluster compounds onto the surface of gold and characterized. The following anionic complexes were used as thin films precursors: [Fe3(CO)9E]2- and [HFe3(CO)9E]-, where E = S, Se, Te. The films were generated by adsorption from organic solvents (e.g., methanol, acetonitrile, acetone, and dichloromethane) onto evaporated gold and were characterized by ellipsometry, polarization-modulation infrared reflection-absorption spectroscopy (PM-IRRAS), X-ray diffraction (XRD), atomic force microscopy (AFM), quartz crystal microbalance (QCM), and X-ray photoelectron spectroscopy (XPS). [Et4N]2[Fe3(CO)9E] catalyzes the carbonylation of methanol to form methyl formate under moderate CO pressures (600--1200 psi) between 50 and 90°C. A detailed kinetic analysis of this system is reported. [Fe3(CO)9E]- selectively carbonylates methanol to methyl formate in a homogeneus reaction which first order dependent in cluster concentration, quasi second order dependent in pressure of CO. The reaction appears to be almost independent of the [OCH 3-]total at values of [OCH3 -]total ≤ 3 x 10-3 M, but at higher concentrations it appears to be first order dependence in [OCH3-]total. This system affords the opportunity to compare the effects of different main group heteroatoms in a homogeneous series.