Aggregation in five-coordinate high-spin natural hemins: determination of solution structure by proton NMR

摘要: {sup 1}H NMR measurements (at 500 MHz) of nuclear spin-spin relaxation time T{sub 2} (from line width) at different temperatures are reported for aggregates several five-coordinate high-spin iron(III) complexes proto-, deutero-, and coproporphyrins in solution utilized to determine their structure. Extensive aggregation these is observed, the dominant form shown be dimers. The degree porphyrins follows order proto- >> deutero- > copro-. width heme methyl resonances was analyzed by using a nonlinear least-squares fit program working finite difference algorithm. values were used structural details dimer.