- Synthesis and characterization of rhenium(III) complexes with (Ph2PCH2CH2)2NR diphosphinoamine ligands
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The synthesis and characterization of a new series of neutral, six-coordinated compounds [ReIIIX3(PNPR)], where X is Cl or Br and PNPR is a diphosphinoamine having the general formula (Ph2PCH2CH2)2NR (R = H, CH3, CH2CH3, CH2CH2CH3, CH2CH2CH2CH3 and CH2CH2OCH3) are reported. Stable [ReIIIX3(PNPR)] complexes were synthesized, in variable yields, starting from precursors where the metal was in different oxidation states (iii and v), by ligand-exchange and/or redox-substitution reactions. The compounds were characterized by elemental analysis, proton NMR spectroscopy, cyclic voltammetry, UV/vis spectroscopy, positive-ion electrospray ionization mass spectrometry (ESI(+)-MS) and X-ray diffraction analysis. Although the formulation of the complexes allows either meridional or facial isomers, the latter arrangement was prevalent both in the solid and solution states. Only [ReCl3(PNPH)] showed a meridional configuration both in solution and in the crystalline state. [ReBr3(PNPme)] prefers the meridional configuration in the crystalline state and the facial one in solution. While ESI(+)-MS and voltammetric data seem to indicate some dependency from the nature of the alkyl substituent at the nitrogen, the available structural data of the complexes show only slight differences both for angles and bond lengths upon change of the alkyl chain tethered to the nitrogen.
- Salvarese, Nicola,Refosco, Fiorenzo,Seraglia, Roberta,Roverso, Marco,Dolmella, Alessandro,Bolzati, Cristina
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supporting information
p. 9180 - 9191
(2017/07/24)
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- Polymerizable Actinic Radiation Curable Composition, Polymerization Method, Actinic Radiation Curable Ink and Image Formation Method, and Ink Jet Recording Apparatus and Epoxy Compound
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A polymerizable actinic radiation curable composition comprising a photo-acid generating compound and an epoxy compound represented by Formula (1): wherein X represents a divalent group selected form the group consisting of —O—, —S—, —SO—, —SO2—, —CBr2—, —C(CBr3)2—, and —C(CF3)2—; R1 to R18 each independently represent a hydrogen atom, a halogen atom, a hydrocarbon group having 1-8 carbon atoms, provided that the hydrocarbon group may contain an oxygen atom or a halogen atom, or a substituted or unsubstituted alkoxy group having 1-8 carbon atoms.
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- Synthesis of 2-γ-N-(aminoethyl)aminopropyl-2-methyl-6-alkyl(aryl,H)-1,3-dioxa-6- aza-2-silacyclooctanes
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Some new 2-γ-N-(aminoethyl)aminopropyl-2-methyl-1,3-dioxa-6-aza-2- silacyclooctane and 2-γ-N-(aminoethyl)aminopropyl-2-methyl-6-alkyl(aryl)-1,3-dioxa-6-aza- 2-silacyclooctanes have been synthesized from γ-chloropropyldimethoxymethyl silane by ethylenediamine substitution and diethanolamine or N-alkyl(aryl)diethanolamines substitution. The resulting silocanes have been characterized by elemental analyses, IR, and 1H NMR.
- Yang,Lin,Li
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p. 2817 - 2822
(2007/10/03)
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- Nucleophilicity towards a Vinylic Carbon Atom: Rate Constants for the Addition of Amines to the 1-Methyl-4-vinylpyridinium Cation in Aqueous Solution
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Second-order rate constants (kNu) have been measured for the addition of 44 primary amines (including five α-effect amines), 28 secondary amines, 19 tertiary amines, ammonia and hydroxide ion to the vinyl group of the 1-methyl-4-vinylpyridinium cation (1) in aqueous solution at 25 deg C (ionic strength 0.1 mol dm-3).Nucleophilic attack is shown to be rate-determining for primary and secondary amines being generally more reactive than primary amines, with secondary amines of the same basicity.After classification of these species in terms of structure, they describe a number of Broensted-type correlations having βnuc in the range 0.35-0.54 for six structural classes of primary amine, βnuc = 0.48 for α-effect amines, and βnuc in the range 0.23-0.34 for four structural classes of secondary amine.Substitution upon the α-carbon atom reduces amine nucleophilicity of both primary and secondary amines.The presence of an unsaturated carbon atom (either sp2- or sp-hybridized) as the β-carbon atom leads to an enhanced reactivity relative to the corresponding β-sp3 species in all cases.Tertiary amines are in general less reactive than other amines of the same basicity.Broensted-type plots for tertiary amines present the appearance of random scatter which is not readily decipherable in terms of structure. β-Hydroxy and β-amino tertiary amines are unusually reactive relative to their basicity.All of these phenomena suggest that protonation of the carbanionic intermediate by a molecule of water is the rate-determining step for the addition of tertiary amines to 1.Rate constants for the attack of primary and secondary amines on 1 are shown to correlate with literature data for a variety of other reactions involving rate-determining nucleophilic attack of amines upon electrophilic carbon.These kNu for primary and secondary amines reacting with 1 are also shown to correlate with Ritchie's N+ parameters for nucleophilic attack at electrophilic sp2-carbon.N+ parameters for amine nucleophiles have not been widely available previously; the parameters that have been available for selected amines are known to be sensitive to the nature of the defining electrophile.The minimal steric hindrance at the electrophilic centre in nucleophilic attack upon 1 suggests that this species is an appropriate electrophile for the definition of N+ parameters for amine nucleophiles; these parameters are evaluated for 70 primary and secondary amines and ammonia and are suggested to provide an appropriate data base for future investigations of the reactivity and selectivity of amine attack upon sp2-carbon electrophiles in aqueous solution.
- Heo, Christina K. M.,Bunting, John W.
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p. 2279 - 2290
(2007/10/02)
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