Titanate molecule

The Six Functions of the Titanate Molecule 93 Table 5.1 Coupling agent chemical description - alpha-numeric code. 

The functional site (1) of the titanate molecule is associated with coupling, dispersion, adhesion, and hydrophobicity effects. These effects are also related to the method of application of the titanate on the filler surface as discussed below. 

Function 1 is capable of forming a chemical bond between the titanate molecule and the filler surface. Improved adhesion is the result. 

Function 2 relates to the ability of the titanate molecule to transesterify. It implies the formation of chemical bonds between the titanate and the polymer matrix containing, for example, groups such as COOH and OH. Titanates can gel polyesters and epoxies and cure alkyds, even though there is no unsaturation in the titanate molecule backbone. 

Function 2 concerns the part of the titanate molecule immediately adjacent to the titanium center and that affects the specific effect, the resistance to hydrolysis, the transesterification activity, and the thermal stabiUty of titanates. This part of the molecule can be represented by the following groups ... 

Thomas JR, Quelch GE, Seidl ET, Schaefer HF HI (1992) The titane molecule (TiHi) equilibrium geometry, infrared and Raman spectra of the first spectroscopically characterized transition metal tetr ydride. J Chem Phys 96 6857-6861... 

Other Inks. The alkan olamine titanates, such as TYZOR TE, when mixed with a coloring agent used to print fibrous materials such as cotton, wool, or silk, promote adhesion of the dye molecule to the fiber, thus minimizing bleeding of the printed design (511). 

These new results only became possible when the groups of H. Waite and B. Magee at the South West Research Institute (SWRI) in San Antonio, Texas, combined analytical data obtained from two different instruments. These are the ion and neutral mass spectrometer (INMS), which obtained data on small to medium-sized molecules in the upper atmosphere of Titan (950-1,150 km) and the Cassini plasma spectrometer (CAPS), which also registered particles from tholins, both positive (100-350 Da) and negative ions (20-8,000 Da) (Waite et al., 2007 Atrey, 2007). 

Of the alkenes (Figure 5.5) only ethene has been detected and of the aromatics only benzene has been seen unambiguously surprisingly propene has not been seen despite its well-understood microwave spectrum. Of interest to the origins of life is the onset of polymerisation in HCN to produce cyanopolyynes. These molecules could provide a backbone for the formation of information-propagating molecules required for self-replication. The survival of these species in a planetary atmosphere depends on the planet oxidation would be rapid in the atmosphere of today s Earth but what of the early Earth or somewhere altogether more alkane-based such as Titan ... 

The volatile-trapping mechanism has a further problem associated with the temperature. Very volatile molecules such as N2, CO and CH4 are not easily trapped in laboratory ice simulation experiments unless the ice temperature is 75 K, which is somewhat lower than the estimated Saturnian subnebula temperature. This has led to the suggestion that the primary source of nitrogen within the Titan surface ices was NH3, which became rapidly photolysed to produce H2 and N2 upon release from the ice. The surface gravity is insufficient to trap the H2 formed and this would be lost to space. However, the origin of methane on Titan is an interesting question. Methane is a minor component of comets, with a CH4/CO ratio of clCT1 compared with the present atmospheric ratio of > 102. The D/H ratio is also intermediate between that of comets and the solar nebula, so there must be an alternative source of methane that maintains the carbon isotope ratio and the D/H isotope ratio and explains the abundance on Titan. 

Essentially, all reactions that require the formation of a chemical bond with an activation energy of around 100 kJ mol-1 are frozen out at the surface of Titan but are considerably faster in the stratosphere, although still rather slow compared with the rates of reaction at 298 K. Chemistry in the atmosphere of Titan will proceed slowly for neutral reactions but faster for ion-molecule reactions and radical-neutral reactions, both of which have low activation barriers. The Arrhenius equation provides the temperature dependence of rates of reactions but we also need to consider the effect of cold temperatures on thermodynamics and in particular equilibrium. 

The formation of the 1,3CH2 methylene radial in either the triplet or singlet electronic states depends on collisions with other molecules such as N2 in the Titan... 

Use Wein s Law to estimate the black body radiation maximum for Titan, expressing your answer in microns and cm-1. Comment on the spectroscopy of molecules in this region of the electromagnetic spectrum. Identify species in Titan s atmosphere that may be photoactive at these wavelengths. 

The photoproduction of CH3+ in Titan s atmosphere initiates a sequence of ion-molecule reactions. The mechanism is as follows ... 

Brack A. 2000. The Molecular Origins of Life. Cambridge University Press Cambridge. Coustenis A. and Taylor F. 1999. Titan The Earth-Like Moon. World Scientific London. Faraday Discussion 109. 1998. Chemistry and Physics of Molecules and Grains in Space. Royal Society of Chemistry London. 

Yi-Jehng Kuan el al. (2004). Searches for interstellar molecules of potential prebiotic importance. Advances in Space Research 33 31-39 Yung Y., Allen M. and Pinto J. (1984). Photochemistry of the atmosphere of Titan comparison between model and observations. Astronomy Astrophysics Supplement... 

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