共 45 条
Synthesis of PDK, a novel porphyrin-linked dicarboxylate ligand
被引:28
作者:
Zhang, XX
[1
]
Lippard, SJ
[1
]
机构:
[1] MIT, Dept Chem, Cambridge, MA 02139 USA
关键词:
D O I:
10.1021/jo000502v
中图分类号:
O62 [有机化学];
学科分类号:
070303 ;
081704 ;
摘要:
A novel trinucleating ligand system H-4(PDK), for porphyrin-based diamine bis(Kemp's triacid)imide, was constructed by using two molecules of Kemp's triacid and one molecule of porphyrin as building blocks. The dimeso-substituted octaalkylporphyrin unit, carrying bromomethyl groups at the ortho positions of two trans-positioned meso-phenyl groups, was synthesized from (3,3'-diethyl-4,4'-dimethyl-2,2'-dipyrrolyl)methane and alpha-bromo-o-tolualdehyde. The structures of both of the two atropisomers (alpha,alpha- and alpha,beta-) of bromoporphyrin, H-2(alpha,alpha-BP) and H-2(alpha,beta-BP), were determined by X-ray crystallography, with the alpha,beta-isomer as the free base form and the alpha,alpha-isomer as the zinc complex. Both the alpha,alpha- and alpha,beta-isomers of the bromomethyl porphyrins were converted to their aminomethyl derivatives, H-2(alpha,alpha-AP) and H-2(alpha,beta-AP), through the corresponding imidoporphyrin intermediates, H-2(alpha,alpha-IP) and H-2(alpha,beta-IP), by the Gabriel synthesis. The alpha,alpha- and alpha,beta- aminoporphyrins were coupled with Kemp's triacid anhydride-chloride to form H-4(alpha,alpha-PDK) and H-4(alpha,beta-PDK), respectively. Unlike the alpha,beta-isomer, the structure of which was determined by X-ray crystallography for the zinc complex, H-4(alpha,alpha-PDK) has a remarkable and complicated solvent-dependent H-1 NMR spectrum that suggests the existence of hydrogen bonding interactions between two convergent, tethered Kemp's triacid units, as predicted in a modeling study. The convergent feature is essential, for the target ligand H-4(alpha,alpha-PDK) to form trinuclear metal complexes with a bis(carboxylato) dimetallic unit sitting above a metalloporphyrin ring.
引用
收藏
页码:5298 / 5305
页数:8
相关论文