Multifunctional Nitrogen

Lubrizol, India has reported [22] a process for the synthesis of an additive for mineral oils. The additive was snythesized by copolymerization of an alkyl methacrylate monomer and a Cs-i2 branched-chain methacrylate such as isodecyl methacrylate using an azo initiation in a hydrocarbon solvent at 50-100°C. This concentrate was further reacted with diethylenetriamine to obtain a multifunctional nitrogen-containing lubricant. Similar nitrogen-containing dispersant VI improvers based on alkyl acrylates or methacrylates for lubricating oils were also prepared by Lubrizol, USA [23]. 

Normally the reaction Is useful for the conversion of alkyl halides to primary amines without concomitant formation of secondary amines.29 Treatment of polymer 17 with hexamethylenetetramine in a mixture of ethanol/THF afforded an insoluble resin. Using diazabicyclooctane (DABCO), we demonstrated that the reaction could be limited to attack by a single nitrogen in a multifunctional amine, so we did not anticipate crosslinking via bis-quat salt formation. Hydrolysis of 2 with anhydrous HC1 in ethanol generated free amino groups as evidenced by a positive ninhydrin test, but quantitative hydrolysis could not be achieved and the product remained insoluble. One would have expected a simple bis-quat to hydrolyse and open the crosslinked structure. 

This enzyme [EC 4.1.3.27] catalyzes the reaction of chorismate with glutamine to generate anthranilate, pyruvate, and glutamate. In certain species, this enzyme is part of a multifunctional protein together with one or more other components of the system for the biosynthesis of tryptophan (Le., indole-3-glycerol-phosphate synthase, anthranilate phosphoribosyltransferase, tryptophan synthase, and phosphoribosylanthranilate isomerase). The anthranilate synthase that is present in these complexes has been reported to be able to utilize either glutamine or ammonia as the nitrogen source. However, it has also been reported that when anthranilate synthase is separated from this complex, only ammonia can serve as a substrate. 

The results of model compound studies with three different types of epoxides, obtained in the presence and absence of ammonium perchlorate are shown in Figures 4, 5, and 6. The epoxide DER-332 shows a uniform rate of disappearance for the acid and epoxide species in this reaction. In the presence of ammonium perchlorate, the rate is increased, and a minimum of side reactions occur. Similar data but faster reaction rates are obtained with Epon X-801, but the consumption of epoxide species by side reactions is increased, particularly in the presence of ammonium perchlorate. On the other hand, the epoxide ERLA-0510 (Table IV), which contains a basic nitrogen, shows a reaction rate which is an order of magnitude greater than that for DER-332, accompanied by a substantial increase in side reactions. In the presence of ammonium perchlorate, the side reactions of ERLA-0510 predominate. In all probability, the side reactions of the multifunctional epoxides studied are homopolymerization. 

Under UV-laser irradiation, photosensitive multifunctional acrylate resins become rapidly cross-linked and completely insoluble. The extent of the reaction was followed continuously by both UV and IR spectroscopy in order to evaluate the rate and quantum yield of the laser-induced polymerization of these photoresist systems. Two basic types of lasers emitting in the UV range were employed, either a continuous wave (C.W.) argon-ion laser, or a pulsed nitrogen laser. 

Figure 1. Reactive oxidized nitrogen species present in the atmosphere. R represents single- or multifunctional organic groups. (Reproduced with permission from reference 57. Copyright 1990 Pergamon Press.)...

This ambivalent interaction behaviour can be explained by the multifunctional structure of this PEI derivative. On the one hand, the divalent metal ions can interact with the nitrogen atoms of the amino groups of the basis polymer, and one the other hand, the methylated moieties lead to an anion exchange character of the polymer. Thus, simultaneous complexation and retention of various elements are feasable with this polymer. 

Figure 2. Nitrogen adsorption isotherms at 77K for the OMM samples with multifunctional mercury-specific ligands 1-benzoyl-3-propylthiourea (OMM-1 and OMM-2), 2,5-dimercapto-1,3,4-thiadiazole (OMM-3) and the corresponding differential pore size distributions. OMM-a, OMM-b and OMM-c refer to the calcined MCM-41, MCM-48 and SBA-15 samples, respectively. For clarity the isotherms are offset vertically by 1000 ccSTP/g for OMM-a and OMM-1 samples and by 500 ccSTP/g for OMM-b and OMM-2 samples. The PSD plots are offset vertically by 2 ccg 1nm 1 for OMM-a and OMM-1 and by lccg-1 nm"1 for OMM-b and OMM-2 samples.

Figure 4. Nitrogen adsorption isotherms recorded at 77K for the PMO samples with multifunctional groups and the corresponding pore size distributions. PMO-1 and PMO-2 contains tris[3-(trimethoxysilyl)propyl]isocyanurate bridging groups only, while PMO-3 and PMO-4 contains tris[3-(trimethoxysilyl)propyl]isocyanurate bridging groups and mercaptopropyl surface ligands. For clarity the isotherms are offset vertically by 400 ccSTP/g for PMO-1, 300 ccSTP/g for PMO-2 and by 100 ccSTP/g for PMO-3.

The design for pyrimidine synthesis differs somewhat from that of purine biosynthesis in that the sugar is attached to the pyrimidine ring at the end of the pathway. In addition, pyrimidine biosynthesis occurs in part in the cytosol and in part in the mitochondria and involves the participation of two multifunctional enzymes. The pathway is summarized in Figure 10.9. One of the initial reactants is the compound carbamoyl phosphate (carbamoyl phosphoric acid). This compound is also formed in the urea biosynthetic pathway, but this takes place in the mitochondria and requires NH3 (Chapter 20). The cytosolic biosynthesis of carbamoyl phosphate for the purpose of pyrimidine biosynthesis requires glutamine as the nitrogen donor ... 

Reaction of a-aminomethylene ketones with biselectrophiles is usually expected to occur at the -position and at the nitrogen of the enaminone under ring closure. However, enaminone chemistry, due to the multifunctional structure, is often characterized by surprising reactions such as rearrangements. 

David HE, Peter MP, Keith PC (2005) The multifunctional fish gill dominant site of gas exchange, osmoregulation, acid—base regulation, and excretion of nitrogenous waste. Physiol Rev 85 97-177... 

Pucci and coworkers recently described a series of multifunctional metallomeso-gens, based on mainly nitrogen and oxygen ligands with a variety of metal centers, some of them innovative such as the rarely encountered Pt(II), Zn(II) and Ga(III)... 

The third concept is the dual-bed emission control catalyst. In this, the catalytic converter is made of two different types of catalyst. The first is either a multifunctional catalyst or at least one capable of promoting NO.v reduction reactions. The engine is calibrated so as to guarantee a net reducing exhaust gas composition. Under these conditions, the first catalyst will lead to an elimination of the nitrogen oxides. The second catalyst is an oxidation catalyst. Extra air is injected in front of the second catalyst to assist the removal of carbon monoxide and hydrocarbons. The secondary air can be added either by mechanically or by electrically driven air pumps. 

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