Protonation of an oxo-bridged diiron unit gives two different iron centers: synthesis and structure of a new class of diiron(III)-μ-hydroxo bisporphyrins and the control of spin states by using counterions.

Protonation of an oxo-bridged diiron unit gives two different iron centers: synthesis and structure of a new class of diiron(III)-μ-hydroxo bisporphyrins and the control of spin states by using counterions.