The isolated C-D stretching vibrations have been studied for a number of selectively monodeuterated species of tetrahydropyran, methyl ethyl ether, methyl propyl ether, methyl butyl ether, methyl hexyl ether, and cyclohexane, and the dependence of the C-D stretching wavenumbers on the conformation of the CO-C(D)-CC, OC-C(D)-CC, and CC-C(D)-CC structures of the alkoxyl chain has been examined. The infrared spectra of three monodeuterated species of tetrahydropyran with a chair form gave definitive evidence for the conformational dependence of the C-D stretching wavenumbers. The observed wavenumbers of the C-D stretching vibrations for the monodeuterated compounds studied are correlated linearly to the C-D bond lengths calculated by the ab initio MO method using the basis set with polarization functions. The dependence of the C-D stretching wavenumbers on the conformational disposition of the C-D bond in the CO-C(D)-CC structure is more significant than that of the C-D bond in the OC-C(D)-CC or CC-C(D)-CC structure. For the CO-C(D)-CC structure, the stretching wavenumbers of the C-D bond trans to the DC-OC and DC-CC bonds are higher by about 90 cm -1 than those of the C-D bond gauche to the same bonds. C-D stretching vibrational spectroscopy has been shown to be one of the advantageous methods for determining the conformation of alkyl chains, which may contain any heterogenous atoms.

Ocean absorption of the CO 2 released to the atmosphere by human activities (i.e., anthropogenic CO 2 ) results in acidification of surface waters as the result of the increase in hydrogen ion (H + ) concentration. The oceanic uptake of anthropogenic CO 2 has decreased ocean pH by 0.1 since the beginning of the industrial era (Intergovernmental Panel on Climate Change, 2013). Ocean acidification also lowers the CaCO 3 saturation state (Ω) by decreasing carbonate ion (CO 3 2− ) concentration with concomitant formation of bicarbonate ions. The carbonate chemistry change affects marine calcifying organisms with carbonate shells and skeletons, marine noncalcifying organism, cellular metabolism, organism physiology, biogeochemical cycling of nutrients, and ecosystems (e.g.,

Typical Ziegler‐type catalysts derived from AIR3 and TiCl4 were found to be effective in the syndiotactic polymerization of methyl methacrylate at low temperatures. The influences of polymerization variables on the polymer yield, the molecular weight of the polymer produced, and the syndiotactic regulating capacity of the catalysts were investigated. In general AlEt3/TiCl4 molar ratios of 3:10 mixing of both the catalyst components and aging of the catalyst system in the temperature range of −30 to 30°C. using aromatic hydrocarbon solvents such as toluene as a polymerization medium, and low polymerization temperature, such as −78°C. are the preferred conditions for the formation of syndiotactic, high molecular weight poly(methyl methacrylate) in high yield. From the results of testing catalyst activities of the separated catalyst systems it was concluded that some cooperation between AIR3 and the insoluble Ti halide compound obtained by the reduction of TiCl4 with AIR3 is essential for the formation of syndiotactic poly(methyl methacrylate).

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