Academic literature on the topic 'Aminotroponiminate'

Catalytic cyanosilylation using platinum compound 3 is reported. Compound 3 is a germylene stabilized platinum(ii) dicyanide, trans-{(ⁱBu)₂ATIGe(ⁱPr)}₂Pt(CN)₂ (ATI = aminotroponiminate).

Thesis (Ph.D.)--Massachusetts Institute of Technology, Dept. of Chemistry, 1999.<br>Vita.<br>Includes bibliographical references.<br>The synthesis and structure of several Zr(IV) carboxylate complexes are described in which the bridging carboxylate is the dianion of 111-xylylenediamine bis(Kemp's triacid imide) (H2XDK) or the more soluble propyl derivative (H2PXDK). Reaction of either H2XDK or H2PXDK with [Zr(CH2Ph)4] or [Zr(NMe2)4] afforded [Zr(CH2Ph)2(XDK)] or [Zr(NMe2)2(XDK)]. [Zr(CH2Ph)2(XDK)] is a rare example of an alkyl zirconium carboxylate complex. [Zr(CH2Ph)2(XDK)] reacts with various pyridine derivatives to yield the 7-coordinate pyridine adduct. An aryl isocyanide (2 equiv) reacts with [Zr(CH2Ph)2(XDK)] to afford the iminoacyl complex [Zr{11 2 -2,6- Me2PhNCCH2Ph}2(XDK)]. [Zr(CH2Ph)2(XDK)] is unreactive, however, towards weak sigma donors such as CO. The eight-coordinate complex [Zr(XDK)2] was formed by either treating [Zr(NMe2)4] with H2XDK (2 equiv) or [Zr(CH2Ph)2(XDK)] with H2XDK. Several of these complexes have been characterized by X-ray crystallography. [Zr(CH2Ph)2(XDK)] is electrophilic since the ipso carbon of one benzyl group is interacting with the Zr center as revealed by the acute Zr-C-C(ipso) angle in the X-ray structure of [Zr(CH2Ph)2(XDK)]. These studies have shown that 6-coordinate Zr carboxylate complexes are electrophilic. Complexes of this type are most stable when they possess high coordination numbers; this trend is exemplified by the stability of [Zr(XDK)2] and [Zr(eta)rt2-2,6-Me2PhNCCH2Phh(XDK)].<br>by Dietrich P. Steinhubel.<br>Ph.D.

Ce travail concerne la synthèse de nano-objets mono-élément (Ge, Sn) et d'alliages (SiGe, GeSn, SnSi) à partir de dérivés du groupe 14 spécialement conçus à cet effet. Ces espèces présentent un double enjeu : elles doivent être suffisamment stables pour les manipuler aisément tout en restant labiles pour les décomposer dans des conditions douces de température. Pour cela, deux séries d'espèces germaniées à basse valence (degré d'oxydation II) ont été préparées et caractérisées. La première présente des ligands N-chélatants (aminotroponiminate et amidinate) permettant une stabilisation par complexation intramoléculaire. Des réactions spécifiques d'oxydation en présence d'une ortho-quinone et de complexation avec des métaux de transition ont confirmé leur caractère divalent. Leur thermolyse en solution a permis l'obtention de nanoparticules photoluminescentes de 2. 5 à 5 nm de diamètre protégées de l'oxydation par un enrobage organique. La seconde série concerne des espèces divalentes di- et poly-métallées du groupe 14 (hypermétallyl-germylènes et -stannylènes) stabilisées par complexation inter- ou intra-moléculaire. Elles pourraient s'avérer être des précurseurs de choix d'alliages nanométriques possédant des propriétés tout à fait inédites<br>This work concerns the synthesis of single-element (Ge, Sn) and alloys (SiGe, GeSn, SnSi) nano-objects from group 14 derivatives specifically designed for this purpose. These species present a double challenge: they have to be stable enough to be handled easily and to remain labile to decompose in mild conditions of temperature. For this, two sets of low-coordinate germanium compounds (oxidation state II) have been prepared and characterized. The first one contains N-chelating ligands (aminotroponiminate and amidinate) which allow stabilization by intramolecular complexation. The oxidative reaction with an ortho-quinone and the complexation reaction with transition metals have confirmed their specific character of divalent sites. Their thermolysis in solution led to photoluminescent nanoparticles with a size in the range of 2. 5 to 5 nm surrounded by an organic layer that protected them from oxidation. The second set was devoted to the synthesis of di- and poly-metallated group 14 complexes (hypermetallyl-germylenes and -stannylenes) stabilized by inter- or intra-molecular complexation. They are potential precursors for group 14 nanoscale alloys with totally unique properties

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Chemistry, 2000.<br>Vita.<br>Includes bibliographical references.<br>Chapter 1. Environmental and Biological Implications of Transition Metal-Nitric Oxide Interactions. This introductory chapter reviews various aspects of NO reactivity by transition metals and in biological systems. Chapter 2. Disproportionation of Nitric Oxide Promoted by a Mn Tropocoronand The first example of a manganese-induced nitric oxide (NO) disproportionation reaction is reported. The synthesis and characterization of divalent [Mn(THF)(TC-5,5)] (1) is presented, along with its reactivity with excess NO to yield N20 and [Mn(NO2)(TC-5,5)] (2). The NO disproportionation involves the formation of a discrete mononitrosyl [Mn(NO)(TC-5,5)j (3), which has been isolated and characterized formally as (MnmNO-) by infrered spectroscopy, normal coordinate analysis, X-ray crystallography and SQUID susceptometry. Chapter 3. NO Disproportionation Reactivity of Fe Tropocoronand Complexes The synthesis and characterization of divalent [Fe(TC-5,5)] (1) and trivalent [Fe(OTf)(TC-5,5)] (2) tropocoronand complexes are described. Compound 1 reacts with one equivalent of NO to form the trigonal bipyramidal (FeNO)7 complex 3, which contains a linearly coordinated nitrosyl (Fe-N-O = 174.3(4)). EPR and M6ssbauer spectroscopy, SQUID susceptometry and normal coordinate analysis indicate 3 to be a low spin (Fem(NO-))2 species. In the presence of excess NO, 3 converts to a metastable nitrosyl-nitrito complex that decomposes by losing NO2. The final products of the NO disproportionation reaction are N2O and [Fe(NO)(TC-5,5-NO2)] (4), a compound that no longer promotes the disproportionation of NO. Mechanistic aspects of the reaction are discussed. Chapter 4. Aminotroponiminates as Ligands for Potential Metal-Based NO Sensors. Part I. Synthesis and Characterization Fluorescently labeled ligands, HRDATI, are described that are composed of aminotroponiminates (ATI) with a dansyl fluorophore on one of the imine nitrogen atoms and an alkyl substituent on the other.<br>(cont.) Bis(chelate) ... complexes were prepared and characterized by X-ray crystallography. The bis-ATI complex [Co(i-Pr2ATI)2] 11 was also prep ared and its X-ray crystal structure determined. When excited at 350 nm, the H DATI ligands and the diamagnetic Zn complex 13 fluoresce around 500 nm, whereas the paramagnetic Co complexes quench the fluorescence. Chapter 5. Aminotroponiminates as Ligands for Potential Metal-Based NO Sensors. Part II. NO Reactivity and Sensing Air-stable cobalt coordination complexes of dansylated aminotroponiminate ligands, [Co(RDATI)2], react with nitric oxide to dissociate a DATI ligand and form neutral dinitrosyl complexes, [Co(NO)2(RDATI)]. The release of the fluorophore-containing ligand is accompanied by an increase in fluorescence intensity, thus providing a strategy for fluorescent NO sensing. Linking two DATI moieties via a 4-methylene chain affords the ligand H2DATI-4. The Co2+ complex [Co(DATI-4)] reacts more readily with NO than the bis-DATI compounds and also demonstrates an increase in fluorescence intensity upon NO binding. Chapter 6. Nitric Oxide Reactivity of Cobalt DenATI, DapATI and Tropocoronand Complexes Dansyl fluorophores are linked to aminotroponiminates via alkyl amine chains to form H2DenATI and H2DapATI ligands ...<br>by Katherine J. Franz.<br>Ph.D.