R. Mathis

Influence de l'environnement moléculaire sur la fréquence de vibration de valence Ge-H. Partie II

Abstract The frequency of the Ge-H valence mode of vibration has been measured for about thirty alkylgermanium hydrides, arylgermanium hydrides and alkyl (or aryl) germanium halogenohydrides. This frequency is raised by −I substituents bound to the germanium atom, and lowered by +I substituents; this effect is generally additive. However, there is, superimposed to it, a steric effect which is quite significant when several voluminous substituents are bound to the germanium atom. No large conjugation effect appears between the d orbital of Ge and the free doublets or π electrons of substituents.

Influence de l'environnement moléculaire sur la fréquence de vibration de valence GeH: Partie III. Influence des solvants

Resume The frequency of Ge-H valence mode of vibration has been measured for several compounds in a variety of solvents. The effect of medium on the frequency is generally slight. This seems to be due to the polarity Ge + H − of the GeH bond, which is unable to form a true hydrogen-bond with proton acceptors.

Etude de quelques composés cycliques polyfonctionnels renfermant le motif CONCO et de leurs dérivés phosphorylés. Liaisons hydrogène et spectres infrarouge

Resume The spectra of compounds containing a phosphoryl bond (P → O) and a heterocyclic ring containing the O  CNC  O system (phthalimide or hydantoin derivatives) have been studied both in the solid state and in various solvents. The spectra of the non phosphorus containing parent compounds are described for comparison. Several type of interactions occur: P → O … CO dipole interaction, NH … OC and NH … O ← P hydrogen bonding. The latter are dependent upon the nature of substituents linked to the phosphorus atom and on the steric requirements of the phosphorus moeity and of the heterocycle.

Aziridines—VIII. Etude en spectographie infrarouge du vibrateur NH (ou ND) dans les aziridines secondaires C-alkylées et C-arylées

Resume We have studied the NH or ND transitions: ν 0–1 , ν0–2, ν0–3 and determinated corresponding anharmonicities (Δν 1–2 and Δν 2–3 ) for about forty aziridines. For only ten of those we have also determined the corresponding intensities: A 0–1 and A 0–2 and variation of frequencies with different solvents. All the results characterize the weakly acid character of the NH proton and give confirmation of the nearly sp 3 hybridation for the nitrogen atom and explain how it is possible to differentiate invertomers with different configuration.

Vibrateur NH et activité antitumorale des cyclophosphazènes vectorisés par des polyamines biogènes

Abstract A comparative i.r. spectroscopic study of NH groups in natural polyamines both free and covalently bound to antitumor cyclophosphazenes allows one to explain the remarkable selectivity towards malignant cells of such drugs when vectorized through such polyamines as tumor finders and to classify the targeting potentiality of these polyamines as a function of the various configurations they adopt when linked to the cyclophosphazenic antitumor agents.

La basicité de l'atome d'azote dans quelques iminophosphanes (PNR) et aminophosphanes (PNR2). Etude en spectrographie infrarouge

Abstract Using i.r. spectroscopy the lone pair basicity of a nitrogen atom on two iminophosphanes (PN-) and six aminophosphanes (PN-) has been estimated. This was done measuring the decreasing Δν XH between ν XH absorption of one XH vibrator (HO- or HN) bonded to a nitrogen atom by hydrogen bonding (PN … HX; PN … HX) and the free absorption ν XH of the same vibrator. For identical substituents on the phosphorus atom, the basicity of nitrogen in iminophosphanes is more important than in aminophosphanes.

Spectres infrarouge et structure de composés cycliques azotés obtenus par l'action des hydrazines sur des derives d'hydrazonates et d'imidates

Abstract Hydrazine and monosubstituted derivatives thereof react with N -2 substituted hydrazonates to give pentagonal heterocyclic compounds: N -aminotriazolones from N -2 ethoxycarbonyl hydrazonates, N -aminotriazoles from N -2 acylhydrazonates. The action of hydrazines on N (methoxycarbonylmethyl) benzimidate leads to derivatives of 1,2,4-tetrazine.

Intensité d'absorption dans l'infra-rouge des bandes de vibration de valence des groupements CC et CH dans quelques composés acétyléniques du germanium

Abstract The absorption intensity of the CC valence vibration in the compounds studied is distinctly greater than that in acetylenic components without a heteroatom; it seems that the former depends on an electrical dissymmetry between the substituents bound to the CC system. There is a decreasing linear relationship between A in the R 3 GeCCR′ and the Taft coefficient σ R′ *, of substituent R′.

Spectres infrarouge d'oxydes d'allénylphosphines XYP(O)CHCCR1R2. Isomerie de rotation. Influence des substituants X et Y sur le dedoublement des bandes d'absorption du système allénique

Abstract Infrared spectroscopic study of compounds XYP(O)CHCCR 1 R 2 reveals the following facts: these compounds exhibit conformational isomerism, presumably arising from rotation about the PC(allenic) bond; the CCC “antisymmetric” stretching vibration frequencies are different for both isomers, and the difference can be correlated with the σ meta Hammett constants of substituents X and Y; the influence of the allenic group on the P → O stretching frequency cannot be entirely accounted for by purely inductive effect; this suggests that the phosphorus atom is in some way conjugated with the allenic system.

Etude en spectrographie infrarouge des groupes liés à un atome de phosphore dans des phosphorhydrazides cycliques et acycliques

Abstract Twenty cyclic or acyclic phosphorhydrazides containing the group have been studied with i.r. spectroscopy. The interaction between the lone pair of atom N 1 and the N 2 H 2 or N 2 HR group is significantly weaker than in ordinary hydrazines. This is interpreted as originating from a partial delocalization of the N 1 doublet towards phosphorus. The ‘spectroscopic acidity’ of N 2 H or N 2 H 2 protons appears as rather low in acyclic or saturated cyclic phosphosphorhydrazides: the electronic state of N 2 nitrogen can be considered as analogous to that of aliphatic amines. This can be related to the comparatively high basicity and nucleophilicity of this atom.