Durand Jérôme, Zangrando Ennio, Stener Mauro, Fronzoni Giovanna, Carfagna Carla, Binotti Barbara, Kamer Paul C J, Müller Christian, Caporali Maria, van Leeuwen Piet W N M, Vogt Dieter, Milani Barbara
Dipartimento di Scienze Chimiche, Università di Trieste Via Licio Giorgieri 1, 34127 Trieste, Italy.
Chemistry. 2006 Oct 10;12(29):7639-51. doi: 10.1002/chem.200501047.
A series of cationic palladium complexes of general formula [Pd(Me)(MeCN)(N-N)][PF(6)] (N-N = (phen) 1 a, 4,7-dichloro-1,10-phenanthroline (4,7-Cl(2)-phen) 2 a, 4,7-diphenyl-1,10-phenanthroline (4,7-Ph(2)-phen) 3 a, 4-methyl-1,10-phenanthroline (4-Me-phen) 4 a, 4,7-dimethyl-1,10-phenanthroline (4,7-Me(2)-phen) 5 a, 5,5,6,6-tetrafluoro-5,6-dihydro-1,10-phenanthroline (F(4)-phen) 6 a, containing different substituted phenanthroline ligands, have been prepared from the corresponding neutral chloro derivatives [Pd(Me)(Cl)(N-N)], (1 b-6 b). The X-ray crystal structure of [Pd(Cl)(2)(4,7-Cl(2)-phen)] (2 b') was determined. DFT calculations show that the electron density on the metal is tuned by the substituents on the ligands. The catalytic behavior of complexes 1 a-6 a in the CO/styrene and CO/p-Me-styrene copolymerizations was studied in detail, showing that the generated catalysts are active for at least 90 h, yielding copolymers of high molecular weight. A firm correlation between the electron density on palladium on the one hand and the catalytic activity of the complexes and the molecular weight and the stereochemistry of the polyketones synthesized on the other hand has been established: the catalyst containing the F(4)-phen is thus far the most active among those tested, yielding the syndiotactic CO/styrene copolymer with a stereoregularity of 96 % (uu triad) and with an M(w) value of 1 000 000.
一系列通式为[Pd(Me)(MeCN)(N-N)][PF(6)]的阳离子钯配合物（N-N = 菲咯啉（phen）1a、4,7-二氯-1,10-菲咯啉（4,7-Cl(2)-phen）2a、4,7-二苯基-1,10-菲咯啉（4,7-Ph(2)-phen）3a、4-甲基-1,10-菲咯啉（4-Me-phen）4a、4,7-二甲基-1,10-菲咯啉（4,7-Me(2)-phen）5a、5,5,6,6-四氟-5,6-二氢-1,10-菲咯啉（F(4)-phen）6a），含有不同取代的菲咯啉配体，由相应的中性氯衍生物[Pd(Me)(Cl)(N-N)]（1b - 6b）制备而成。测定了[Pd(Cl)(2)(4,7-Cl(2)-phen)]（2b'）的X射线晶体结构。密度泛函理论计算表明，配体上的取代基可调节金属上的电子密度。详细研究了配合物1a - 6a在CO/苯乙烯和CO/p-甲基苯乙烯共聚反应中的催化行为，结果表明生成的催化剂至少90小时内具有活性，可得到高分子量的共聚物。已建立了一方面钯上的电子密度与另一方面配合物的催化活性、合成的聚酮的分子量和立体化学之间的紧密关联：含F(4)-phen的催化剂是迄今为止测试的催化剂中活性最高的，可得到间规度为96%（uu三联体）且M(w)值为1000000的CO/苯乙烯间规共聚物。
