Liquid terminal group

A complete set of intermolecular potential functions has been developed for use in computer simulations of proteins in their native environment. Parameters have been reported for 25 peptide residues as well as the common neutral and charged terminal groups. The potential functions have the simple Coulomb plus Lennard-Jones form and are compatible with the widely used models for water, TIP4P, TIP3P and SPC. The parameters were obtained and tested primarily in conjunction with Monte Carlo statistical mechanics simulations of 36 pure organic liquids and numerous aqueous solutions of organic ions representative of subunits in the side chains and backbones of proteins... 

The proposed structure for the polymer is well supported by liquid state ll, 13C, and nB NMR data and elemental analysis. The formula, BN16C15H3 5, is consistent with the theoretical N/B ratio of 1.7. Since no chlorine is detected in the product, the terminating groups are mainly borylamino, N(CH3)B(NHCH3)2, groups. 

In contrast to the uniform dendrimer, a polydisperse hyperbranched polymer with OH-terminal groups showed only one transition corresponding to the collapse from the monolayer of flatly spread molecules to a disordered liquid. Dendrimer 1 is similar to dendrimer 2 in Fig. 8, except the difference in branch ends (CH3 vs OH), did not spread and exhibited no structural transitions upon compression. 

Anionic polymerization has also been used to make telechelic polymers (Greek telos, end, and chele, claw), i.e., polymers with reactive terminal groups.We coined the term, telechelic in 1957 and it has been accepted ever since in technical as well as patent literature. Liquid carboxy- and hydroxy telechelic polybutadienes initiated with difunctional organolithium initiators are commercially produced since 1962. Some of the physical properties,production details and uses as in solid rockets... 

The curing of liquid thiokol is based on the reaction of the liquid polymer with lead dioxide or peroxides. Dehydrogenation of the terminal groups of the mercaptan chains of the polymer then takes place followed by elongation of the chains. This reaction may be depicted as ... 

The degree of polymerization is dictated by the ratio of liquid resin (cmde DGEBPA) to bisphenol A an excess of the former provides epoxy terminal groups. The actual molecular weights attained depend on the purity of the starting material. Reactive monofunctional groups act as chain terminators. 

Crown ethers discussed in this section possess rod-like substituents all around them or flat substituents at either end (Fig. 14). The former was the structure of the first liquid crystalline crown-like molecules and will be discussed first. The latter one comprises molecules with taper- or disk-shaped terminal groups. 

A low melting point is preferable in order to avoid metastable, monotropic liquid crystalline phases. Low-temperature mesoporphic behaviour in general is technologically more useful, and alkyl terminal groups promote this. 

The unique spectrum when in the liquid crystalline state is due to the resonance phenomenon exhibited by the two terminal groups and the conjugated carbon chain between them, and the ability of electrons to be shared between the individual molecules of the liquid crystal. 

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