Trovacene Chemistry. 16, 1,1a‐Di([5]trovacenyl)‐1,1,1a,1a‐tetraphenyl‐disiloxane: Electro‐ and Magneto‐Communication Across a Si‐O‐Si Spacer

By means of lithiation and subsequent derivatization [5]trovacenyl-diphenylsilanol (2·), di([5]trovacenyl)tetraphenyl-disiloxane (3··), di([5]trovacenyl)tetramethyl-disiloxane (4··) and di([5]trovacenyldimethylsilyl)methane (6··) have been prepared and characterized by X-ray diffraction (2·, 3··, 6··). Although the bond angles of the disiloxane bridges differ considerably, magnetic exchange interaction in these organometallic diradicals is practically unaffected as shown by fluid solution EPR spectroscopy. By way of contrast, electrocommunication clearly responds to change in the structure of the SiOSi spacer in that the redox splittings derived from cyclic voltammetry display the gradation δE1/2 (0/–/2–) 4·· < 6·· < 3··. It is proposed that in this order electronic polarizability in the intervening spacer increases thereby facilitating the transmission of electrostatic effects.