Coordination polymers absorption

Although dimethylberyllium is a coordination polymer in the solid state,27 it has long been known to be monomeric in the gas phase.28 It has also been found to be monomeric when synthesized from the co-condensation of laser-ablated beryllium atoms and a methane/argon mixture at 10 K.11 Formed in conjunction with several other species, including hydrides (see Section 2.02.2.4), (CH3)2Be was identified from its infrared absorption bands, which were compared to DFT-calculated frequencies (DFT = density functional theory). 

This hypothesis is further supported by the effect on the absorption behavior of molecular oxygen of additives that destroy the a-helix of PLL. When we added to the PLL system non-coordinative polymers, which do not act as ligands but are able to interact with PLL to form polymer aggregates, the cooperative parameter decreased to unity, as shown in Table 11. In these cases, it was found that the a-heli-cal conformation was made unstable by the formation of polymer aggregates111 ... 

Remarkably, the aqueous solutions of the coordination polymers were shown to reversibly transform from transparent to translucent states above certain temperatures. At high temperatures, absorption spectra of coordination polymers were significantly... 

Fig. 2 X-ray structures of (a) discrete Zn 2(ld(o)) complexes and (b) Cu 2(o) linear coordination polymers, (c) Polarised absorption spectra of M 2(o). (d) Polar plot of polarized absorption of Zn 2(o) measured at 620 nm. Reprinted (adapted) with permission from (K. Matsuda, K. Takayama and M. Irie, Inorganic Chemistry, 2003,43, 482 89). Copyright (2003) American Chemical Society.

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