The bonding interactions of phosphines and carbenes with a transition metal center have been explored with gas-phase photoelectron spectroscopy and computational methods. The interactions governing the electronic differences between these two species are probed in order to comment on differences in reactivity that are seen in transition-metal catalytic species. The principles governing the nature of sigma and pi bonding for phosphines and carbenes have been explored and quantified. The electronic bonding factors of the ligand L in the (L)₂(CL)₂Ru=CHPh have been probed in order to explain the catalytic reactivity differences in Grubb's first generation bisphosphine species where L = tricyclohexylphosphine (PCy₃) to the second generation ruthenium catalyst where an N-heteocyclic carbene (NHC) 1,3-dimesityl-imidazolidine-2-ylidene (H₂IMes) replaces one of the phosphines in the catalyst. To directly compare the bonding modes of PCy₃ and NHCs, the (CO)₅MoL system is utilized in order to take advantage of its high symmetry. Results indicate that the NHC ligands are stronger σ donors than phosphines, and essentially have no π-acceptor ability. These electronic differences have key implications to the differences these catalyst exhibit in terms of initiation and propagation. Next, the bonding in the Cp*Ru(Cl)L molecules, where L = PCy₃, PⁱPr₃, H₂IMes, IMes and Prⁱ₂Me₂Im, is explored by photoelectron spectroscopic investigations and supporting electronic structure calculations. The Cp*Ru(Cl)L system is a coordinatively unsaturated 16 electron system which can electronically and satirically bind small molecules. This system has been found to have electronic structure interactions similar to half-sandwich complexes. In addition, the ionization energies measured from the photoelectron spectra of Cp*Ru(C)L molecules correlate well to solution calorimetry measurements of bond energies by Nolan and co-workers. Finally, the nature of a rare "internal" transition metal iridium carbene is probed via gas-phase photoelectron spectroscopy and density functional calculations. Ionizations measured for the [IrCl(ᵗBu₂PCH₂CH₂CCH₂CH₂PᵗBu₂)] complex with the support of theoretical calculations serve to establish the valency of the iridium metal center. This internal pincer has been found to have a "covalent carbene-metal" interaction.

Gas-phase photoelectron spectroscopy was utilized to study a series of metal-metal bonded complexes. Molecular mechanics, Fenske-Hall and ab-initio theoretical calculations were performed on many of the systems. The central focus of all the studies was to identify metal-metal ionizations, and observe how ligands effects influence metal-metal interactions. This information was then used to describe various physical and chemical properties of the species. The first group of compounds studied were molybdenum and tungsten D₃(h) triply-bonded hexa-alkoxides of the form M₂(OC(CH₃)n(CF₃)₃₋n)₆ (where M=Mo, W and n = 1, 2, 3). The metal-metal π and σ ionizations were identified. It is observed that sequential fluorination of the ligands shifts all the valence ionizations. Because the shifts are found to be dominated by charge effects, the virtual levels are assumed to be equally shifted. This information was used to describe the similarity of the UV absorption spectra of the compounds. The next group studied are electron-rich single-bonded Rh(II)-Rh(II) complexes. The previously assigned PES data for Mo₂(O₂CCF₃)₄ was used as a reference point when interpreting the data for Rh₂(O₂CCF₃)₄. The electron configuration orbital ordering for the Rh-Rh bond in Rh₂(O₂CCF₃)₄ is determined to be σ²π⁴δ²δ*²π*⁴, with the δ* and π* being nearly degenerate. It is observed that if the acetates are replaced with more electron-donating ligands, as with Rh₂(O₂CCF₃)₂(form)₂, Rh₂(form)₄ (form = N-N’-p-tolylformamidine, C₁₅H₁₅N₂) and Rh₂(dpf)₄ (dpf = diphenylformamidine, C₁₃H₁₁N₂), the δ* ionizations are destabilized relative to the other Rh-Rh ionizations. In addition, ligand-based ionizations overlap into metal-metal ionizations making it more difficult to interpret data. This information is then used to understand the data and electron structures of Rh₂(pfb)₄ (pfb = perfluorobutyrate, CF₃(CF₂)₂CO₂⁻), Rh₂(capy)₄ (capy = caprolactamate, ⁻OC(CH₂)₅N), Rh₂(OCCH₃NC₆H₅)₄ and Rh₂(OCCH₃NC₆F₅)₄. Rh₂(OCCH₃NC₆H₅)₄ and Rh₂(OCCH₃NC₆F₅)₄ provide examples where charge and overlap effects can be utilized to assign Rh-Rh ionizations. Rh₂(pfb)₄ and Rh₂(capy)₄ exhibit very high and different product selectivities when employed as catalysts in reactions involving carbenes derived from diazo-carbonyl complexes. A mechanism for this catalysis is derived which correlates with the observed selectivities.

Cyclopentadienyl bis(imido) complexes of molybdenum, prepared from Mo(=NAr)₂Cl₂(THF)₂ (Ar = 2,6-diisopropylphenyl) and one equivalent NaCp or LiCp’ [Cp=η⁵- C₅H₅ (1), Cp’ = η⁵- C₅H₄CH₃ (7)], are described. These complexes undergo metathesis with alkyl Gringard reagents to produce the alkyl derivatives CpMo(=NAr)₂R [R = Me (2), Et (3), ⁱPr (4), allyl (5)] or Cp’Mo(=NAr)₂Me (8). Complexes 1-8 do not exhibit reactivity similar to their isolobal tris(imido) analogs and are unreactive towards additional electrophiles and nucleophiles under a variety of conditions. An unprecedented terminal cyclopentadienylidene complex of tantalum has been formed from reacting CpTa(NEt)₂Cl₂ (11) and 2 equivalents MeLi. Deuterium labeling studies show that CpTa(NEt₂)₂(=CC₄H₄) (12) is formed via a pathway that involves intermolecular C-W bond activation of a C₅H₅ ligand. Complex 12 is observed to undergo thermally induced intramolecular β-H abstraction from an ancillary NEt₂ ligand to eliminate the organic imine EtN=CHMe (23) and produce the tantalocene hydride complex (η⁵- C₅H₅)₂Ta(η²-EtN=CHMe)H (22). [Zr(μ-NAr)Me₂(THF)]₂ (26), Zr(=NAr) Me₂py₂ (27) and W(=NAr’)₂Me₂py (28, Ar’ = 2,6-dimethylphenyl) represent the first dimethyl complexes of these respective classes of early transition metal imido compounds. Complexes 26-28 are observed to contain nucleophilic imido nitrogens. Thus, Zr(=NAr)Me₂py₂ (27) reacts with 2 equivalents of H₂NAr to produce the previously synthesized Zr(=NAr)(NHAr)₂py₂ but the reaction of 27 with HOAr’ results in the elimination of CH₄. W(=NAr’)₂Me₂py (28) reacts with HOAr’ and H₂NAr in reactions that releases an imido ligand from the complex as aniline. Complexes 26-28 react with H⁻ sources to provide unidentifiable organometallic products, CH₄, and in the case of W(=NAr’)₂Me₂py, H₂NAr. The insertion of ᵗBuN=C into one of the W-Me bonds of complex 28 to give the η²-iminoacyl product W(=NAr’)₂Me(η²-C(=NᵗBu)Mepy (31). The relevance of these complexes and reactions to the fundamental C-N bond scission and heterocycle degradation steps in hydrodenitrogenation catalysis will be described.

Reduction of Ta(DIPP)₂Cl·OEt₂(DIPP= 2,6-OC₆H₃ⁱPr₂) with 2 equiv. of NaHg in the presence of 3,5-lutidine results in cyclometalation of DIPP to give TaCl(DIPP)-(OC₆H₃ⁱPr-η²(C,C)-CMe =CH₂)(3,5-lutidine)₂ (10) in moderate yield. Metallacycle 10 was also isolated from the reaction of (η⁶-C₆Me₆)Ta(DIPP)₂Cl with 3,5-lutidine. Examination of both crude reaction mixtures by ¹H NMR revealed 10 to be the major product without any indication of the formation of η²-lutidine species. These observations suggest that η²(N,C)-coordination of 3,5-lutidine is kinetically incompetitive with respect to the cyclometalation of DIPP by d² tantalum. Such undesired reactivity of DIPP can be potentially inhibited by the use of linked aryloxide ligands to prevent close approach of metalatable C-H bonds of DIPP to the metal center. An efficient route to a family of silane-linked aryloxides was developed. Tris(2-hydroxy-3-isopropylphenyl)methylsilane (H₃TIPSI, 59), bis(2-hydroxy-3-isopropyl-phenyl)diphenylsilane (H₂BIPSI, 61), and bis(2-hydroxy-3-isopropylphenyl)dimethyl-silane (H₂BIPSI, 60) were obtained via deprotection of the parent silane-linked anisoles. The anisoles were prepared in high yields by treating 2-methoxy-3-isopropyl-phenyllithium·0.5TMEDA (27·0.5TMEDA) with an appropriate amount of chloroalkylsilanes. The deprotection was carried out employing BBr₃ in CH₂Cl₂ followed by hydrolysis of the intermediate boron ethers in the presence of a non-nucleophilic base to avoid protiodesilylation. Additionally, a significantly improved synthesis of 1,2-bis(3-isopropyl-2-hydroxyphenyl)ethane (H₂BIPP, 40) employing 27·0.5TMEDA as a starting reagent is reported. 2-Methoxyphenyllithium 27·0.5TMEDA was prepared via catalytic ortho-directed metalation of 2-isopropylanisole, and the mechanistic aspects of such metalations are presented. Trinuclear complex (AlBr₂)₃TIPSI (55) was isolated from the reaction of Me₃TISPI with 3 equiv. of AlBr₃ in benzene at 60°C. Preliminary reactivity studies show that Me₃TIPSI (49) and Me₂BIPSI (51) can be reacted with TaBr₅ under similar conditions to give Br₃Ta(MeTIPSI)(THF)₂ (62) and Br₃Ta(BIPP)OEt₂ (63), respectively, after appropriate reaction work ups.

The MoOS₃ active site of sulfite oxidase has drawn attention to a relatively unexplored area of molybdenum coordination chemistry. Cis,trans-(L-N₂S₂)MoᵛO(SR)[L-N₂S₂H₂ = N,N '-dimethyl-N,N'-bis(mercaptophenyl)ethylenediamine: R = CH₂Ph. CH₂CH₃, and p-C₆H₄-Y (Y = CF₃, Cl, Br, F, H, CH₃, CH₂CH₃, and OCH₃)] are the first structurally, spectroscopically, and electrochemically characterized mononuclear Mo compounds with three thiolate donors in the equatorial, as occurs in sulfite oxidase. These compounds provide a well-defined platform for the systematic investigation of the electronic structures of the MoᵛOS₃ centers and their implications for molybdoenzymes. Single crystal electron paramagnetic resonance spectroscopy was used to study cis,trans-(L-N₂S₂)MoᵛOCl and determine the relationship between the molecular and magnetic structure. These studies furnish a better understanding of the CW-EPR parameters exhibited by the various Mo(V) forms of the mononuclear molybdenum enzymes.

Three series of acetylide complexes have been examined by gas phase ultraviolet photoelectron spectroscopy to elucidate the electronic structure and bonding of the acetylide to the metal. The electronic properties of the metal fragments and the acetylides were varied in these systems to understand how the acetylide σ and π systems bond to a metal center. The first series of complexes probes the extent of metal-metal electronic communication through the conjugated, acetylide bridged ruthenium dimer compound [(η⁵-C₅H₅)Ru(CO)₂]₂(μ-C≡C). The broad envelope of overlapping metal ionizations seen in the dimer compound compared to the "monomer" (η⁵-C₅H₅)Ru(CO)₂C≡C-CH₃ revealed extensive metal-metal communication through the acetylide bridge. Also observed was a stabilization of metal ionizations in the ruthenium compounds compared to analogous iron compounds. The second series of acetylide complexes probes the bonding effects of increasing the electron richness at the metal center coupled with increasing electron withdrawing capability on the acetylide. The complexes under examination were of the general formula (η⁵-C₅H₅)ML₂C≡C-R (M = Fe, Ru, L = CO, R = p-C₆H₄-NO₂; M = Ru, L = P(CH₃)₃, R = C₆H₅, p-C₆H₄-NO₂] . Ancillary ligand substitution of trimethylphosphine for carbonyl increased the electron richness at the metal center, and the electron withdrawing capability of the acetylide was increased by para substitution of a nitro group on the phenylacetylide. The filled/filled interaction between the metal-dπ/acetylide-π orbitals dominates the metal-acetylide bonding picture in all of the compounds. Nitro substitution on the phenylacetylide resulted in a substantial inductive charge shift, but minimal π effects were observed. Nitro substituted phenyl derivitives showed similar bonding to the acetylides. The third series of complexes probes acetylide bonding with the M₂R₄P₄ core [M = Mo, P = PMe₃, and R = C≡C-Si(CH₃)₃, C≡C-C(CH₃)₃]. A different bonding picture was revealed in the molybdenum series, with the metal-metal- δ orbital having a filled/filled interaction with the acetylide π orbital, as well as donating electron density into the empty acetylide π* orbital. The effects of silicon substitution on the acetylide is probed by comparing ᵗButylacetylene with trimethylsilylacetylene.

The subject of this dissertation is the development of synthetic methods to allow the employment of the hexanuclear octahedral [Re₆(μ₃-Se)₈]²⁺ cluster core as both a structural component in host materials and as a novel photoactive Lewis acid catalyst. The first chapter describes the first method, cluster condensation, and its application in the preparation in a series of cluster-supported molecular squares. The squares, of the general formula cyclo-[Re₆(μ₃-Se)₈(PR₃)₄(L)]₄(SbF₆)₈ (R=Et, Ph; L=4,4'-dipyndyl derivative), use the cis-coordination mode of the starting material cis-[Re₆(μ₃-Se)₈(PEt ₃)₄(MeCN)₂](SbF₆)₂ as the sole structure directing component. The reaction is shown to be useful for small cyclic species and discrete molecules which feature more elaborate ligands. Based on the limitations of the cluster condensation reaction, a different approach to cluster linkage formation is developed in Chapters two and three. In the interest of continuing the expression of cluster stereochemistry in assemblies larger than the squares, these chapters introduce monocluster complexes featuring secondary functionality placed at the ends of pyridyl based ligands. These secondary functions are moieties capable of hydrogen bonding and metal ion coordination. Chapter three describes a range of hydrogen bound polymers and the use of cluster stereochemistry to dictate their dimension and shape. Chapter four elaborates a series of clusters linked by coordination to secondary metal ions forming porous and nonporous coordination polymers. The rational use of cis-[Re₆(μ₃-Se)₈(PPh₃)₄(4,4'dipyridyl)₂](SbF₆)₂ as a shape directing ligand results in the creation a chain of fused squares and a related zig-zag polymer which can also be created by direct conversion of the square chain structure. Chapter five describes the design of a novel photoactivated Lewis acid catalyst for the preparation of imino esters based on the activated nitrile of [Re₆(μ₃-Se)₈(PEt₃)₅(MeCN)](SbF₆)₂. The synthesis and subsequent photolysis of two imino ester complexes is recounted. Chapter six summarizes the dissertation and proposes some future experiments.

The synthesis, characterization, and reactivity of three-fold (1σ, 2π) donor complexes of tungsten and tantalum have been explored. (η⁵-C₅Me₅)W(=NAr)₂Cl (1) has been prepared from the reaction of W(=NAr)₂Cl₂(THF)₂ with Li(C₅Me₅). Complex 1 can be functionalized by sigma-donor ligands, but 1 reacts with 1σ, 1π donors such as 2,6-diisopropylphenylamide to give the intramolecular C-H bond activated product, (η⁵-C₅Me₄CH₂)W(=NAr)₂(5). [(η⁵-C₅Me₅)Ta(=NAr)₂Cl)]⁻ was synthesized by reacting (η⁵-C₅Me₅)TaCl₄ or (η⁵-C₅Me₅)Ta(NAr)Cl₂ (6) with excess of 2,6-diisopropylphenylamide. The mechanism of formation of [(η⁵-C₅Me₅)Ta(=NAr)₂Cl)]⁻ was investigated. Structures of (η⁵-C₅Me₅)W(=NAr)₂Cl (1) and [Li(OEt₂)][(η⁵-C₅Me₅)Ta(NAr)₂Cl] (7) are reported.

A number of organometallic complexes involving manganese, bonded to silicon, tin, lead and phosphorus ligands, and nickel, bonded to various trialkylphosphine ligands, has been synthesized and their crystal structures, vibrational, and multinuclear magnetic resonance spectra have been obtained. The FT-IR and FT-Raman spectra of the manganese carbonyl compounds in the carbonyl region (2200--1850 cm--1) have been assigned. Solid-state, CP-MAS, 13C, 29Si, 31P, 117Sn, 119Sn and 207Pb NMR spectra of substituted pentacarbonylmanganese(I) and tetracarbonylmanganese(I) complexes feature asymmetric sextets, whereas those containing a group 14 (IVA) element bridging two pentacarbonylmanganese(I) moieties show asymmetric sextets. The uneven splitting arises from spin-spin coupling and second-order quadrupole-dipole effects, which are not eliminated by magic angle spinning. The solid-state NMR spectra of the manganese complexes have been analyzed to give the isotropic chemical shifts, the chemical shift tensors, one-bond spin-spin coupling constants, 55Mn nuclear quadrupole coupling constants, effective dipolar coupling constants and the anisotropies; in the spin-spin coupling for each complex. The results provide new insights into the relationship between spin-spin coupling and quadrupolar coupling in bimetallic complexes involving a quadrupole transition-metal and a spin-1/2 nucleus. / For the para-substituted triaryltin complexes, the 13C, 55Mn and 119Sn chemical shifts and one-bond spin-spin constants in solution show excellent correlations with pairs of substituent constants (sigmaI, sigmaR). However, there is no correlation of the chemical shifts or spin-spin coupling with either Hammett (sigmaP) or Taft (sigmaP o) constants or the Mn-Sn bond lengths, rMn-Sn. The results obtained from dual substituent parameter (DSP) analysis indicate that both resonance effects (sigmaR) and inductive effects (sigma I) are important in determining the NMR parameters. / Crystal structures and high-resolution solution and solid-state 31P NMR spectra were obtained for several dihalobis(trialkylphosphine)nickel(II) complexes. The crystal structures and NMR results indicate that these complexes are trans square-planar in the solid-state. The chemical shifts and shift tensors were obtained and found to vary with the electronic properties of the halogens. The 31P isotropic chemical shifts in the solution spectra of dibromo- and diiodiobis(tribenzylphosphine)nickel(II) are very different from those found for the solid-state, and chemical exchange effects were observed in all spectra. The mechanism of exchange appears to involve the formation of dimers with bridging halides.

The catalytic reduction of nitrous oxide (N2O) to dinitrogen (N2) by nitrous oxide reductase (N2OR) is poorly understood. The N2O molecule is a poor ligand with relatively sparse coordination chemistry. We proposed the synthesis of probable nitrous oxide precursors which can be coordinated to transition metals prior to conversion to nitrous oxide. Nitramide, H2NNO2, 2-1, and the related nitrogen amide acids N-nitroamide 2-2, 2-3; N-nitrocarbamate 2-4, 2-5, N-nitrosocarbamate 2-6, 2-7; N-nitrosulfonamide 2-8 have been synthesized as possible nitrous oxide precursors for coordination studies with transition metals. The silver salts of the conjugate base of the nitrogen acids N-nitroamide 2-2Ag; N-nitrocarbamate 2-4Ag, 2-5Ag; N-nitrosocarbamate 2-6Ag; N-nitrosulfonamide 2-8Ag are synthesized from the reaction of the acids with Ag2CO3. Similarly the potassium salts of the nitrogen acids N-nitroamide 2-2K; N-nitrocarbamate 2-4K; N-nitrosocarbamate 2-6K; N-nitrosulfonamide 2-8K are synthesized from the reaction of the nitrogen acids with K2CO3 or CH3OK. To investigate the pi-acidity of the nitrogen acids, a series of Ir(I) complexes of the nitrogen acids, trans-Ir(η1-X)(CO)(PPh3)2, (X = nitrogen acid) N-nitroamide 3-3; N-nitrocarbamate 3-4, 3-5; N-nitrosocarbamate 3-6; N-nitrosulfonamide 3-7 are synthesized from the reaction of Vaska's complex, trans-Ir(Cl)(CO)(PPh3)2 (3-1) with the silver salts of the conjugate base of the nitrogen acids (N-nitroamide 2-2Ag; N-nitrocarbamate 2-4Ag, 2-5Ag; N-nitrosocarbamate 2-6Ag; N-nitrosulfonamide 2-8Ag). Comparative studies with the related amides, dinitramide and bistriflimide, have also been done.The oxidative addition of the nitrogen acids (N-nitroamide 2-2, 2-3; N-nitrocarbamate 2-4, 2-5) to trans-Ir(Cl)(N2)(PPh3)2 (3-2) afford the Ir(III) complexes of the nitrogen acids, Ir(η2-X)(H)(Cl)(PPh3)2, (X = nitrogen acid) N-nitroamide 3-11, 3-12; N-nitrocarbamate 3-13, 3-14. The 31P, 1H NMR and IR spectroscopic reaction monitoring profiles of the oxidative addition reactions give evidence of reaction intermediates that eventually convert to the final product. The reaction of 3-11 with CO and P(CH3)2Ph result in the formation of multiple isomers of the addition products and also phosphine substitution. Addition of methyl triflate to 3-11 in CH3CN is found to result in the substitution and loss of the nitrogen acid. The Re(I) complexes of the nitrogen acids , trans-Re(η2-X)(CO)2(PPh3)2, (X = nitrogen acid) N-nitroamide 4-8; N-nitrocarbamate 4-9; N-nitrosulfonamide 4-12 are synthesized from the reaction of trans-[Re(CH3CN)2(CO)2(PPh3)2](Y), (Y = ClO4: 4-3, BF4: 4-7) with the potassium salts of the conjugate base of the nitrogen acids 2-2K, 2-4K and 2-8K respectively. The reaction of 4-7 with N-nitrosocarbamate 2-6K at room temperature gives mostly the kinetic isomer trans-Re(η2-X)(CO)2(PPh3)2 (4-10). The same reaction at reflux conditions gives mostly a thermodynamic isomer Re(η2-X)(CO)2(PPh3)2 (4-11A). Complex 4-9 and 4-10 are found to crystallize in an unusual space group R-3 that gives a large unit cell with huge solvent channels between the Re complexes and CH2Cl2 solvate molecules. The Dimroth/amidine rearrangement of benzotriazoles has been shown to exist in solution for 5-1 by variable temperature 19F NMR. The reaction of 3-2 with the benzotriazoles 5-1 and 5-2 gives the new Ir(I) complex, trans-Ir(Cl)(η1-5-1)(PPh3)2 (5-7) and Ir(III) complex, trans-Ir(Cl)(η3-5-2)(PPh3)2 (5-8) respectively. Complex 5-7 undergoes addition and substitution reactions readily to give multiple isomers while 5-8 is inert towards nucleophiles. / La réduction de l'oxyde nitreux (N2O) en diazote (N2) par le réductase de l'oxyde nitreux (N2OR) est très peu comprise. La molécule N2O n'est pas un très bon ligand et à une coordination chimique limité. Nous proposons la synthèse de précurseurs de l'oxyde nitreux qui peuvent se coordonner aux métaux de transitions avant leurs conversions en oxyde nitreux. Nitramide, H2NNO2, 2-1, et les acides d'azotes amidés N-nitroamide 2-2, 2-3; N-nitrocarbamate 2-4, 2-5, N-nitrosocarbamate 2-6, 2-7; N-nitrosulfonamide 2-8 ont étés synthétisés en tant que de possible précurseurs de l'oxyde nitreux pour des études de coordination avec des métaux de transitions. Les sels d'argents des bases conjugués des acides d'azotes N-nitroamide 2-2Ag; N-nitrocarbamate 2-4Ag, 2-5Ag; N-nitrosocarbamate 2-6Ag; N-nitrosulfonamide 2-8Ag ont étés synthétisés par les réactions des ces acides avec Ag2CO3. Similairement, les sels de potassium des bases conjugués des acides d'azotes N-nitroamide 2-2K; N-nitrocarbamate 2-4K; N-nitrosocarbamate 2-6K; N-nitrosulfonamide 2-8K ont étés synthétisés par les réactions des ces acides soit avec K2CO3 ou CH3OK. Pour examiner l'acidité du système pi de ces acides d'azotes, des séries the complexes d'acides d'azotes d'Ir(I) trans-Ir(η1-X)(CO)(PPh3)2, (X = acide d'azote) N-nitroamide 3-3; N-nitrocarbamate 3-4, 3-5; N-nitrosocarbamate 3-6; N-nitrosulfonamide 3-7 ont étés étés synthétisés par les réactions du complexe de Vaska, trans-Ir(Cl)(CO)(PPh3)2 (3-1), avec les sels d'argents des bases conjugués des acides d'azotes (N-nitroamide 2-2Ag; N-nitrocarbamate 2-4Ag, 2-5Ag; N-nitrosocarbamate 2-6Ag; N-nitrosulfonamide 2-8Ag). Des études comparatives avec des amides reliés, dinitramide et bistriflimide, ont aussi étés faites. Les complexes de Re(I) des acides d'azotes, trans-Re(η2-X)(CO)2(PPh3)2, (X = acide d'azote) N-nitroamide 4-8; N-nitrocarbamate 4-9; N-nitrosulfonamide 4-12 ont étés synthétisés par les réactions de trans-[Re(CH3CN)2(CO)2(PPh3)2](Y), (Y = ClO4: 4-3, BF4: 4-7) aves les sels de potassium des bases conjugués des acides d'azotes 2-2K, 2-4K et 2-8K respectivement. La réaction de 4-7 avec N-nitrosocarbamate 2-6K à température de la pièce procure principalement l'isomère cinétique trans-Re(η2-X)(CO)2(PPh3)2 (4-10). La même réaction en condition de reflux procure principalement l'isomère thermodynamique Re(η2-X)(CO)2(PPh3)2 (4-11A). Les complexes 4-9 et 4-10 cristallisent dans un groupe d'espace insolite, soit R-3, qui à une grande unité cellulaire avec de larges canaux de solvant entre les complexes de Re et les molécules de solvant de CH2Cl2.Le réarrangement Dimroth/amidine des benzotriazoles ont démontré leur existence en solution pour 5-1 via la RMN 19F en température variable. Les réactions de 3-2 avec les benzotriazoles 5-1 et 5-2 donnent de nouveaux complexes d'Ir(I), trans-Ir(Cl)(η1-5-1)(PPh3)2 (5-7) et d'Ir(III), trans-Ir(Cl)(η3-5-2)(PPh3)2 (5-8) respectivement. Le complexe 5-7 subit facilement des réactions de substitution et d'addition pour donner de multiples isomères tandis que le complexe 5-8 est inerte envers les nucléophiles.