Copolymerization of carbon monoxide and norbornadiene with a palladium catalyst

Pd complexes of (RR)- and (SS)-1,5-methylbenzyl-3,7-diphenyl-1,5-diaza-3,7-diphosphacyclooctane as catalysts in alternating cooligomerization of CO with dienes

“…The cooligomerization rate is low, but comparative with the data obtained by another authors (Table 1) [5,[18][19][20][21]. The rate of CO absorption in cooligomerization reaction decreases with time ( Fig.…”

Polyimides with side groups: Synthesis and effects of side groups on their properties

“…Liaw and Liaw synthesized symmetric and unsymmetric diamines 3 and 4 with tert-butyls respectively through the nucleophilic displacement reaction of p-chloronitrobenzene and 2,5-di-tertbutylhydroquinone (or tert-butylhydroquinone) with K 2 CO 3 and then hydrazine reduction with Pd/C as shown in Scheme 11. 82,83 Hsiao et al synthesized a similar diamine with tertbutyls 5 by the same method. 84 On the other hand, he still prepared a dianhydride 6 with tert-butyls from 4nitrophthalonitrile and tert-butylhydroquinone by a substitution reaction, and then nitrile groups were hydrolyzed and cyclodehydrated to afford 6 in Scheme 12.…”

“…Exceptionally, the introduction of tert-butyl just slightly decreased the thermal stability of polyimides and most of them are stable up to 450 8C. [76][77][78][79][80][81][82][83][84][85][86][87][88][89][90] In addition, we found the number of tert-butyl affect the T g of polyimides, for example, polyimides prepared from diamnie 14 containing two tert-butyls displayed higher T g than that of those prepared from diamine 13 containing one tert-butyl. 80 The strong hindrance of tert-butyl decreases the movement ability of polyimide chains and results in an increase in T g ( Table 1).…”

“…5) with different side groups are selected to further demonstrate the effect of side groups on thermal properties of polyimides. 83,94,[113][114][115][116][117] The temperature at 10% weight loss under N 2 (T 10 ) of traditional aromatic polyimide 1,4-BAPBz-PMDA are 604 8C. When phenyl or trifluoromethyl was introduced into polyimides, the T 10 decreased 21 8C for PI-8 or 29 8C for PI-5 comparing with that of 1,4-BAPBz-PMDA.…”

Alternating Copolymers of Carbon Monoxide 2. Copolymers of Co and Dienes

“…The polymer, with M n around 2900, had a melting point below 300°C, was soluble in benzene, chloroform and TGF, but when left to stand in air (perhaps as a result of oxidation) its solubility deteriorated. It became possible to create a copolymer with a higher yield using complexes of palladium with bidentate P^P and N^N ligands [8,16]. Sen [17] synthesised a copolymer of CO and norbornadiene with a [Pd(CH 3 CN) 2 (PPh 3 ) 2 ](BF 4 ) 2 catalyst (60°C, 56 atm CO) that was soluble in CHCl 3 and C 6 H 6 and had MM = 3380.…”