The acid and base catalyzed simultaneous twin polymerization to produce ternary organic–inorganic nanostructured hybrid materials consisting of a cross-linked phenolic resin, silica and a disubstituted polysiloxane.
1‐Bis(carboxymethyl)amino‐butandion‐2,3‐dioxim H4A bildet in saurer Lösung oktaedrische 1,1‐Komplexe MII(H2A)(H2O)x (MII = Cu, Mi, Co), in denen es vierzählig über die Iminodiessigsäure‐ und die Oximgruppe in 2‐Stellung koordiniert. Ni(H2A)(H2O)x und Cu(H2A) (H2O) unterliegen im neutralen Gebiet der Deprotonierung; im Falle des Nickel(II) entsteht neben Ni(HA)− auch das binucleare Chelat [Ni2(HA)2]2−. In Lösungen mit einem Ligandenüberschuß kann der planare Komplex [Ni(HA)2]4− mit dem Donatorsatz N4 nachgewiesen werden. Beim übergang von [Ni(HA)]− in [Ni(HA)2]4− wechselt das Nickel(II) die Koordinationssphäre; gleichzeitig erfolgt die Cis‐trans‐Isomerisierung mindestens einer Oximgruppe.
Protonierungs‐ und Komplexstabilitätskonstanten sowie die Eigenschaften kristalliner Komplexe werden mitgeteilt.
The reaction of isocyanates with substituted imidazolines and the thermally induced cleavage of the resulting adducts are presented. For this purpose, reactions of various isocyanates [ethyl isocyanate, p-methylphenyl isocyanate, phenyl isocyanate, p-(trifluoromethyl)phenyl isocyanate] with 1-alkylimidazoline derivatives have been studied as a function of the substituent at the 2-position of the imidazoline ring. Three equivalents of isocyanate react with one equivalent of 1-ethylimidazoline to give a stoichiometric well-defined adduct. However, 1-ethyl-2-isopropylimidazoline reacts with isocyanates at 0 °C in another way, with formation of 2:1 adducts which belong to the family of 1,3-diphenyltetrahydroimidazo[1,2-a][1,3,5]triazine-2,4(1H,3H)-diones. The reaction of 1-ethyl-2-methylimidazoline with aromatic isocyanates at 0 °C also leads to 2:1 adducts, in this case of a malonamide type, which can react at 60 °C with an additional isocyanate equivalent to give the known pyrimidinediones. Thermal analysis (TG-MS/DSC) and trapping reactions with nucleophilic reagents, such as diphenylamine, show the release of isocyanate during the thermally induced cleavage reaction. Thus, blocked isocyanates are available by the reaction of isocyanates with 1-ethylimidazoline or 1-ethyl-2-isopropylimidazoline.
Die Reaktion der Thioamide (I) mit POCl3 und der entsprechenden Amide (IV) mit PSCl3 führt zu dem selben Gleichgewicht zwischen Amiden, Thioamiden und den Komplexen (II) und (III).
Durch Reaktion des Dioxims (I) mit Na‐iminodiacetat im neutralen Bereich wird der Titelligand (II) dargestellt, der in saurer Lösung (pH 2‐4,5) die oktaedrischen 1:1‐Komplexe (III) bildet, in denen er vierzähnig über die Iminodiessigsäure‐ und die Oximgruppe in 2‐Stellung koordiniert.
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