Multifunctional Organic

As an organic polymer, poly(tetramethylene oxide) was also used for the preparation of ceramers. The mechanical properties in these cases were much improved in comparison with those for hybrids from polysiloxanes. In these poly (tetramethylene oxide)-silica hybrids, the effect of the number of functional triethoxysilyl groups was examined [13]. As shown in Fig. 2, more multifunctional organic polymer produced more crosslinked hybrid networks. This means that the more rigid the structure in the hybrids is, the higher the modulus and the lower swelling property. 

Copper(II) oxide and cobalt(II) hydroxide form cements with solutions of many multifunctional organic acids propanetricarboxylic acid, tartaric acid, malic acid, pyruvic acid, mellitic acid, gallic acid, tannic acid and phytic acid (Allen et al., 1984 Prosser et al., 1986). These have been used mainly in cement devices for the sustained release of copper and cobalt (Manston et al., 1985 Mansion Gleed, 1985). Little is known about... 

Pekala R.W., Alviso C.T., Kong F.M., Hulsey S.S. Aerogels derived from multifunctional organic monomers. J. Nn-Cryst Solids 1992 145 90-8. 

Chemoselectivity is often a major issue in the reduction of multifunctional organic substrates such as substituted conjugated enones. The corresponding unsaturated alcohols have found use as building blocks for pharmaceutically active molecules for example (i-amino-a-phenylethanol is used for the synthesis of (5-blockers which are the active molecules for controlling hypertension and other cardiac disorders. 

Multifunctional organics are also possible contributors. Nielsen et al. (1998) have examined the possible contribution of multifunctional compounds to missing NOy in both the gas and particle phases. As discussed in Chapter 9, compounds with sufficiently high vapor pressures (> 2x 10 5 Torr) exist essentially completely in the gas phase, those with low vapor pressures (< 2 X 10 9 Torr) in the condensed phase (i.e., on or in particles), and those in between the two extremes as both gases and particles. Nielsen and co-workers have developed a relationship between the expected vapor... 

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.)...

A number of other theoretical and laboratory studies have predicted the existence of alkyl and multifunctional organic nitrates in the atmosphere (9, 49-56). The atmospheric chemistry of the organic nitrates was recently reviewed (57). 

Measurements of these relatively minor species will not only complete the budget of NO, but will also indicate if our understanding of the hydrocarbon oxidation schemes in the atmosphere is complete. The organic nitrates that completed the NO, budget in the example in Figure 9 arose primarily from the oxidation of the naturally emitted hydrocarbon, isoprene (2-methylbutadiene). To demonstrate the oxidation mechanisms believed to be involved in the production of multifunctional organic nitrates, a partial OH oxidation sequence for isoprene is discussed. The reaction pathways described are modeled closely to those described in reference 52 for propene. The first step in this oxidation is addition of the hydroxyl radical across a double bond. Subsequent addition of 02 results in the formation of a peroxy radical. With the two double bonds present in isoprene, there are four possible isomers, as shown in reactions 2-5 ... 

This account has summarized several of our approaches to the preparation of electric-field-aligned chromophoric polymers for second order NLO applications. Molecular design has been employed wherever possible to arrive at structures that probe particular aspects of the polar orientation issue. The rich variety of accessible organic structures has enabled us to consider the orientation problem from a variety of points of view, and to indicate by example the manner in which multifunctional organic synthesis may play a role in the fabrication of oriented materials. 

The selective oxidation of multifunctional organic molecules to give products of greater value is an important target in the fine chemicals industry. 

Figure 3. Schematic representation of PMOs with multifunctional organic bridging groups and bifunctional PMOs with multifunctional bridging groups and mercaptopropyl surface ligands.

It is shown that OMSs and PMOs with multifunctional organic ligands possess a high capacity towards mercury ions, which is due to the accessible pore network and high concentration of multifunctional ligands. Especially... 

Porous Polymers (Tenax, XAD, Chromosorb) Higher boiling-point organics acidic and basic organics, multifunctional organics, pesticides, polynuclear aromatic hydrocarbons, etc. 

The use of aldolases and transketolase has opened the way to many highly multifunctional organic compounds [1]. In organic synthesis, the most widely used dihydroxyacetonephosphate (DHAP) aldolase is the commercially available fruc-tose-1,6-bisphosphate aldolase from rabbit muscle (FruA). This enzyme is a key enzyme of the glycolytic pathway, reversibly catalyzing the cleavage of fructose-... 

Related molybdenum catalysts appear to show even more functional group tolerance. To date, the major test of functional group compatibility has been in the synthesis of polymers however, it is anticipated that this activity will persist into acyclic metathesis. Later transition metals are active in the metathesis polymerization of highly functiondized cyclic alkenes. These catalyst systems, which appear to tolerate almost all functional groups, show very low activity for acyclic alkene metathesis. If these systems can be activated, the problems associated with the use of alkene metathesis in the synthesis of multifunctional organics will be solved. 

Fig. 3. Some examples of multifunctional organic linker molecules a) lactic acid, b) oxalic acid, c) adipic acid, d) azelaic acid, e) malonamide, f) oxodiacetate, g) iminodiacetate, h) oxypyridine-4-carboxylic acid, i) squaric acid, j) 1,3-benzenedicarboxylic acid, k) 1,3,5-benzenetricarboxylic acid, 1) isonicotinic acid, m) 2,6-pyridine dicarboxyUc acid, n) 3,5-pyrazoledicarboxyUc acid, o) 4,4 -dipyridyl...

Extensive research has been conducted in the field of multi-photon spectroscopy for the past several decades. However, until recently, multi-photon processes did not find widespread applications due to the small multi-photon absorptivity of materials. The contributions from several research groups to develop a new generation of multifunctional organic materials with sufficiently large multi-photon absorption cross-sections have opened up a number of novel applications in photonics and biophotonics. 

Production of Multifunctional Organic Acids from Renewable Resources... 

Lactic acid (2-hydroxypropionic acid) is a naturally occurring multifunctional organic acid that is found in many food products, particularly in those which involve natural or processed fermented food preparations. Currently, more than 70% of lactic acid is used as acidulents, food preservatives, and feedstock for the manufacture of calcium stearoyl-2-lactylates in the baking industry. The consumption of lactic acid is estimated to be around 30 million lb in the US with an estimated increase of 6% per year. Therefore, lactic acid is an intermediate-volume specialty chemical used chiefly for food processing. 

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