P-C BOND ACTIVATION AND ETA-4-COORDINATION OF ARENE - X-RAY CRYSTAL-STRUCTURE OF A DINUCLEAR MU-PHOSPHIDO MU-ETA-2-ETA-2-PHENOXO ZWITTERIONIC COMPLEX OF PALLADIUM TRAPPING AN AGGREGATE OF 3 HYDROGEN-BONDED PHENOL MOLECULES

Pd[P(tBu)3]2 reacts photochemically with an excess of phenol in n-hexane to give the dinuclear complex [{P(tBu)2H}2Pd2{mu-P(tBu)2}(mu-eta-2:eta-2-C6H5O)] . 3 C6H5OH (1); X-ray crystallography shows a linear chain of three phenol molecules hydrogen-bonded to the phenoxide ligand which is eta-4-coordinated to the Pd2 framework. The pi coordination of the phenoxide ring is retained in solution, as evidenced by H-1-NMR spectroscopy.