THE REDOX BEHAVIOR OF FERROCENE MOLECULES .12. THE REDOX BEHAVIOR OF SOME BIS-FERROCENYL COMPOUNDS - CRYSTAL AND MOLECULAR-STRUCTURES OF DIFERROCENYLMETHANE AND DIFERROCENYLMETHANOL

Electrochemistry of diferrocenylmethane (1), diferrocenylketone (2), d iferrocenylmethanol (3), diferrocenyl(phenyl)methanol (4), bis(1-ferro cenylpropyl) ether (5), 3,3-bis(ferrocenylmethyl)pentane-2,4-dione (6) , 2,2-bis(ferrocenylmethyl)cyclohexane-1,3-dione (7) and trans-1,2-dif errocenylethene (8) shows that one-electron oxidation of the individua l ferrocenyl sub-units takes place through: (i) separated charge trans fers for 2 and 4; (ii) nearly overlapping steps for 1, 3 and 8; and (i ii) single steps for each of 5, 6 and 7. This reflects the extent of e lectronic communication between the two redox centres, which is relati vely high in the first case, decreases for the second series and is ne gligible for the third series. The crystal structure of diferrocenylme thanol 3 demonstrates that in the solid state the molecules are aggreg ated into centrosymmetric pairs with an O ... O distance of 3.020(3) A ngstrom. The hydroxyl hydrogen atoms are disordered, but one pattern o f site occupancy gives rise to a closed (OH)(2) dimer with hydrogen-bo nding graph set R(2)(2)(4). The crystal structure of diferrocenylmetha ne 1 contains isolated molecules having almost the same conformation a nd molecular volume as 3.