Showing papers by "Instituto Superior Técnico published in 1980"
TL;DR: In this article, N, N-Dimethylaminoalkyl and N-methyl-N-phenylaminyl esters of 1- and 2-naphthoic acid, 9-anthroic acid and 3-pyrenoic acids exhibit excited intramolecular charge transfer interactions which lead to quenching of the fluorescence of the ester.
62 citations
TL;DR: In this paper, the interconversion of carbyne and hydride complexes derived from protonations oftrans-[M(CNMe)2(dppe)2](M = Mo or W) has been studied.
Abstract: The interconversion of carbyne, carbyne and hydride complexes derived from protonations oftrans-[M(CNMe)2(dppe)2](M = Mo or W) has been studied. The initial site of protonation is shown to be the isonitrile nitrogen and all protonations proceed through the common carbyne intermediatetrans-[M(CNHMe)(CNMe)(dppe)2]+. The CNHMe group in traps-[M(CNHMe)2(dppe)2]2+ is shown to be susceptible to electrophilic attack at N and nucleophilic attack at ligating C, the new complexestrans-[W(CNH2Me)(CNHMe)(dppe)2](BF4)3 andtrans-[Mo(CHNHMe)(CNHMe)(dppe)2]BF4 being formed, respectively.
45 citations
TL;DR: In this paper, the authors compared the results obtained from thin target measurements with the theoretical results pertaining to the SCA and PWBA theories, calculated taking into account electron binding energy, projectile Coulomb retardation and electronic relativistic effects.
29 citations
TL;DR: In this article, the spectroscopic properties of complexes between benzo-15crown-5 and europium and terbium nitrates, thiocyanates and perchlorates were investigated.
29 citations
TL;DR: Isonitriles et al. as mentioned in this paper showed that trans-Mo(N 2 ) 2 (PMePh2) 4 ) can displace dinitrogen quantitatively from cis and trans in benzene under tungsten light irradiation.
20 citations
TL;DR: In this article, the tetrahedral metallocene derivatives [M(η-C5H5)2X2], [M[M[C5 H5]2HX] and [M [C5 HO5]3][PF6] with ligands imidazole, N-methylimidazoles, pyrazole and 2,2′-bisimidazolate gave a wide range of new mono and bi-nuclear complexes.
18 citations
TL;DR: In this paper, the metallocene derivatives of 2-vinylpyridine and 4-vyridine were compared with the corresponding ligand derivatives, including acrylonitrile and allylcyanide derivatives.
15 citations
TL;DR: For t-BuNC substitution, the only detected intermediate appears to be [Mo(CNBu-t)(PMe 2 Ph) 4 ] and no intermediate was detected in reactions of trans-[Mo(N 2 ) 2 (Ph 2 PCH 2 CH 2 PPh 2PPh 2 ] with CNMe as mentioned in this paper.
12 citations
TL;DR: In this paper, the authors showed that the treatment of the mixture [W2(CNMe)4(μ-CNHMe)2(PMe2Ph)4]2+ cation with H2SO4 or [Et2OH][BF4] gives methylamine, ammonia and methane.
Abstract: Treatment oftrans-[Mo(CNMe)2(PMe2Ph)4] andme-[W(CNMe)3(PMe2Ph)3] with sulphuric or hydrochloric acids in methanol or ethanol, or in methanol alone, under irradiation, gives methylamine, ammonia and hydrocarbons (mainly methane). The complex [W2(CNMe)4(μ-CNHMe)2(PMe2Ph)4]2+ cation has been obtained by the treatment ofmer-[W(CNMe)3(PMe2Ph3] with H2SO4 or [Et2OH][BF4] and gives methylamine, ammonia and methane on further acid treatment.
9 citations
TL;DR: The electrochemical behavior of these complexes in acetonitrile has been studied by cyclic voltammetry and constant potential electrolysis at platinum electrodes as mentioned in this paper, and the complexes undergo two reversible one-electron reductions to species which are stable on the cyclic voltage-ammetry time scale, but the uptake of electrons appears to be followed by loss of the triazenido ligand.
7 citations
TL;DR: In this paper, the intramolecular exciplex formed from N,N-methylphenyl 2-ethyl-(2-naphthoyl)amine was studied by time-resolved emission spectroscopy using a cavity-dumped argon ion laser (wavelength, λ = 257.25 nm).
TL;DR: In this article, reaction-solution calorimetric measurements of reactions of M(η-C5H5)2H2 (c) (M = Mo, W) with carbon tetrabromide in toluene led to bond-enthalpy contributions D (MoBr) = 242.0 kJ mol−1 and D (Wbr) = 298.9 kJmol−1