Synthesis and Properties of 1,1‐bis{[3‐(N,N‐Dimethylamino)propyl]amido}alkane‐di‐N‐oxides

Abstract

A homologous series of new surface-active 1,1-bis{ [3-(N,N-dimethylamino)propyl]amido}alkane-di-Noxides were synthesized in the reaction of an appropriate diethyl 2-alkylmalonate with N,N-dimethylamino-1,3-propanediamine followed by oxidation with aqueous hydrogen peroxide. The adsorption isotherms of their aqueous solutions were measured and evaluated to obtain adsorption parameters: critical micelle concentration (CMC), surface excess concentration (G CMC ), equilibrium surface tension at the CMC (c CMC ), cross-sectional area of the adsorbed surfactant molecule (A CMC ), efficiency of surface adsorption (pC 20 ), standard free energies of adsorption (DG°a ds ), and micellization (DG°C MC ). All investigated di-amidoamines and di-N-oxides were practically non-toxic to selected bacteria and yeasts. These compounds are readily biodegradable in the Closed Bottle Test inoculated with activated sludge. Surface and biological properties showed that this group of N-oxide-type compounds has high surface activity and fulfills requirements for environmental acceptance.

BifunctionalN‐Oxides of Alkyldiamidoamines

“…The value of the calculated increment DlogCMC/CH 2 (very well known as Kleven's constant [20]) was equal to 0.47. This value was much higher than the value 0.32 determined recently by us for similar 1,1-bis{ [3-(N,N-dimethylamino)propyl]-amido} alkane-di-N-oxides [12] and values obtained for other double-headed surfactants: 0.27 for N-alkyl-N,N-bis[3-(lactobionylamido)propyl]amines [8], 0.33 for long-chain alkyl-diglycosides [5], but similar to value 0.44 obtained by Czichocki [2] for N-alkanoyl-N,N-bis [2-(gluconylamido) ethyl]amines. This value is also comparable with values obtained for amphoteric and nonionic single-headed surfactants: 0.47, and 0.46 for N-alkyl betaines and N-alkyl-N,N-dimethylamine oxides, respectively (calculated from data presented in [21]) or 0.49 for oxyethylenated alcohols (calculated from data presented in [17]).…”

“…Although short-chain homologues of 1,1-bis{[3-(N, N-dimethylamino)ethyl]amido}-alkane-di-N-oxides, 4, are less surface-active than the analogous 1,1-bis{[3-(N, N-dimethyl-amino)propyl]amido}alkane-di-N-oxides [12], due to significant difference in DlogCMC/CH 2 values between them, compounds with long alkyl substituents R showed comparable surface activity. …”

“…Recently, we have investigated dicephalic-type di-N-oxides derivatives of 2-alkylmalonic acid holding two fragments of N,N-dimethylamino-1,3-propanediamine [12] which are very highly surface-active, practically nontoxic and readily biodegradable surfactants.…”

Environmentally responsive adsorption and assembly behaviors from N-alkyl-1,2-ethylenediamines

“…Between the empirical equation of CmN2N at pH ¼ 2.0 and that of alkylammonium chloride (CmNH 3 Cl, log cmc ¼ 1.25 À 0.295 Â m) at 25 C, 46 where all surfactants are fully protonated, no signicant difference can be observed except that the cmc of CmNH 3 Cl is slightly smaller than that of CmN2N at pH ¼ 2.0 with the same m. This means that the chemical combination of an additional amino group in the hydrophilic headgroup increased the hydrophilicity but decreased the micellization ability of the surfactant, which has also been observed in the bifunctional N-oxides of alkyldiamidoamines. 47,48 Similarly to cmc, when m increases, the values of g cmc are also decreased at pH ¼ 2.0 and 7.5, following the general rule of surfactants. This is because surfactants with longer alkyl chains adsorb more strongly at the air-water interface than shorter ones due to the stronger hydrophobic interaction and this results in a lower g cmc .…”

Synthesis and Surface Properties of Dicephalic Surfactants with a 1,3‐Dioxane Ring

“…Surface active, non-toxic and biodegradable di-aldo(bio)namides derivatives of N-alkyl-N,N-bis(3-aminopropyl)amines were investigated by Wilk et al [6]. Recently we have investigated dicephalic derivatives of 2-alkylmalonic acid with two polar N-oxide groupings [7].…”