The η4-o-Benzoquinone Manganese Tricarbonyl Anion (o-QMTC) as an Organometalloligand in the Formation of M(o-QMTC)2(L−L) Complexes (M = Mn, Co, Cd; L−L = bipy, phen): Generation of Neutral 2-D Networks Containing Two Types of π−π Stacking

Incorporation of Fe3O4 nanoparticles into organometallic coordination polymers by nanoparticle surface modification

Surface-modified Fe(3)O(4) nanoparticles (NPs) can be obtained by substituting [(eta(5)-semiquinone)Mn(CO)(3)] for oleylamine surface protecting groups. The resulting NP can function as a nucleus or template to generate crystalline coordination polymers that contain superparamagnetic Fe(3)O(4) NPs. Hybridized magnetic properties can be obtained by introducing paramagnetic metal nodes, such as Mn(2+), into the polymers (see picture).

π-Bonded quinonoid transition-metal complexes

Coordination of the carbocyclic ring of hydroquinones to electrophilic transition-metal fragments such as Mn(CO)3+ and Rh(COD)+ produces stable pi-bonded eta6-complexes that are activated to facile reversible deprotonation of the -OH groups. The deprotonations are accompanied by electron transfer to the transition metal, which acts as an internal oxidizing agent or electron sink. With manganese as the metal, the resulting eta5-semiquinone and eta4-quinone complexes have been used to synthesize one- two- and three-dimensional polymeric metal-organometallic coordination networks. With rhodium as the metal, the pi-quinonoid complexes have been demonstrated to play a unique role in multifunctional C-C coupling catalysis and in the synthesis of new organolithium reagents. Both classes of pi-quinonoid complexes appear to have significant applications in nanochemistry by providing an excellent vehicle for templating the directed self-assembly of nanoparticles into functional materials.