Temperature metal coordination polymers

Oligomerization and polymerization of terminal alkynes may provide materials with interesting conductivity and (nonlinear) optical properties. Phenylacetylene and 4-ethynyltoluene were polymerized in water/methanol homogeneous solutions and in water/chloroform biphasic systems using [RhCl(CO)(TPPTS)2] and [IrCl(CO)(TPPTS)2] as catalysts [37], The complexes themselves were rather inefficient, however, the catalytic activity could be substantially increased by addition of MesNO in order to remove the carbonyl ligand from the coordination sphere of the metals. The polymers obtained had an average molecular mass of = 3150-16300. The rhodium catalyst worked at room temperature providing polymers with cis-transoid structure, while [IrCl(CO)(TPPTS)2] required 80 °C and led to the formation of frani -polymers. 

In the solid-state structure of dilithiated fluoranthene (235), generated from 234 in dimethoxyethane at room temperature by Bock and coworkers (Scheme 82), lithium-DME units are capping the naphthalene moiety from both sides of the plane alternatingly (compound 235 forms a coordination polymer in the solid state). The metallic lithium, used for the reaction, was activated by ultrasonic irradiation. Moreover, several structures of related polysodium compounds were also characterized in the solid state . 

The more stable of the two organic ligands is completely volatilized below 200°C., and even the zinc complex is fully sublimed at 325°C. On the other hand, the zinc coordination polymer has only lost 68% by weight at 1000°C. and must be heated at this elevated temperature for about 8 hours before it is essentially completely volatilized. The zinc polymer is unique in this respect because the metallic zinc formed on thermal degradation is volatile at 1000°C. in vacuo, while the metallic residues remaining after decomposition of the other coordination polymers are not volatile under these conditions. 

The highly crosslinked, three-dimensional network structure of the Cr(III) coordination polymer is considerably more stable at elevated temperatures than the Zn(II) polymer or the other transition metal polymers which have been studied. For example, while the Cr(III) sample sustains a loss in weight of about 30% at 850°C., the Zn(II) coordination polymer loses 60% under similar conditions. 

Several drawbacks limit the utility of the hybrid metal oxides prepared to date. Firstly, it has proven extremely difficult to create materials with porosity as high as is in coordination polymers. This is especially true in the case of materials with two- and three-dimensional M-O-M frameworks. Secondly, while some examples of these materials have relatively high magnetic ordering temperatures, there are still no examples that order at or above room temperature. However, there do not appear to be any fundamental reasons why these difficulties cannot be overcome. 

Transition metal coordination of Cu(II) carboxylate groups and pyridine groups was employed as a means of coupling a telechelic butadiene-base polymer with a randomly functionalized styrenic polymer. Dynamic mechanical analysis (DMA) and differential scanning calorimetry (DSC) indicated partial miscibility of the two polymers and Fourier transform infrared (FTIR) spectroscopy demonstrated that interactions occurred on a molecular level. When compared with blends of PSVP and the free acid derivative of CTB, the compositions based on the transition metal complex had improved dimensional stability at elevated temperatures, though there remains some question as to the stability of the copper salt to hydrolysis. Electron spin resonance (ESR) spectroscopy showed that only the... 

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