| Organobimetallics based upon fulvalene have been intensely studied during the last decade. This thesis deals with dibenzofulvalenes and their organometallic derivatives, prepared in the hope of enhancing the reactivity of fulvalene complexes through operation of the indenyl effect.; Dibenzo (b,e) fulvalene appears to be as reactive as its quinonoid structure would suggest; reactions intended to form it invariably gave polymeric products. A TCNE adduct was isolated and characterized.; Diiron complexes of dibenzo (b,e) fulvalene have continually eluded our grasp, however, two novel bridged products were obtained in reactions of doubly deprotonated 2,2{dollar}sp{lcub}prime{rcub}{dollar}-biindenyl (9) with {dollar}rm Fesb2(CO)sb9/Fe(CO)sb4Isb2{dollar} (giving 51) and with {dollar}rm CpFe(CO)sb2Br{dollar} (giving 73a). Reaction of dibenzo (a,d) fulvalene with {dollar}rm Fesb2(CO)sb9{dollar} gave labile mono- and bis-{dollar}rmlbrack Fe(CO)sb4rbrack {dollar} derivatives along with products thought to be {dollar}rm Fesb3(CO)sb8{dollar} (86) and {dollar}rm Fesb2(CO)sb5{dollar} (89) complexes.; Chromium and molybdenum complexes of the dibenzofulvalenes have been obtained by first forming bis({dollar}etasp6){dollar}complexes of the dienes 9 and 1,1{dollar}sp{lcub}prime{rcub}{dollar}-biindenyl. Deprotonation of these resulted in double metal migration to form bis{dollar}(etasp5){dollar}dianions, which were oxidized by ferrocenium ion to the metal-metal bonded {dollar}(mu ,etasp5{lcub}:{rcub}etasp5{dollar}-dibenzofulvalene){dollar}rm Msb2(CO)sb6{dollar} products. {dollar}(mu ,etasp5{lcub}:{rcub}etasp5{dollar}-dibenzo (a,d) fulvalene){dollar}rm Wsb2(CO)sb6{dollar} was made directly from 1,1{dollar}sp{lcub}prime{rcub}{dollar}-biindenyl and {dollar}rm W(CO)sb3Pysb3.{dollar} Crystal structures of the (a,f) - and (b,e) -{dollar}(mu ,etasp5{lcub}:{rcub}etasp5{dollar}-dibenzofulvalene){dollar}rm Mosb2(CO)sb6{dollar} complexes and the trimethylphosphite derivative {dollar}(mu ,etasp5{lcub}:{rcub}etasp5{dollar}-dibenzo (a,d) fulvalene) {dollar}rm Mosb2(CO)sb5TMP{dollar} showed Mo-Mo bond lengths of 3.286(4), 3.3485(6), and 3.3172(8) A, respectively, all shorter than in {dollar}(mu ,etasp5{lcub}:{rcub}etasp5{dollar}-fulvalene){dollar}rm Mosb2(CO)sb6{dollar} (3.371(1) A). All four compounds showed comparable degrees of ligand pyramidalization, as measured by the bend angle {dollar}omega{dollar}, a better measure than the previously used dihedral angle {dollar}theta{dollar}.; Among the reagents tried, only halogens added readily to the Mo-Mo bonds of these complexes. The failure of numerous reagents to insert into the Mo-Mo bonds or to form Mo-X-Mo linkages from the bis{dollar}(etasp5){dollar}dianions casts doubt on the hypothesis that the fulvalene ligands weaken the bonds through stretching.; The indenyl effect was manifested in (a) the high reactivity of {dollar}(mu ,etasp5{lcub}:{rcub}etasp5{dollar}-dibenzo (b,e) fulvalene){dollar}rm Mosb2(CO)sb6{dollar} toward trimethylphosphine (to form 99); (b) the efficient thermal reaction with alkynes to form {dollar}(mu ,etasp5{lcub}:{rcub}etasp5{dollar}-dibenzofulvalene){dollar}rm Mosb2(CO)sb4(mu ,etasp2{lcub}:{rcub}etasp2{dollar}-alkyne); and (c) facile demetallation reactions. Fluxional behavior in the 4-octyne adducts showed a significantly lower barrier in the (a,d) complex, attributed to ground state steric destabilization, than in the fulvalene or (b,e) analogues.; The di-molybdenum hexacarbonyl complexes were shown to catalyze the addition of {dollar}rm CClsb4{dollar} to 1-hexene, with the effectiveness decreasing in the sequence (b,e) complex {dollar}>{dollar} ({dollar}rm CpMo(CO)sb3rbrack sb2 >{dollar} (a,d) complex {dollar}{lcub}>{rcub} (mu ,etasp5{lcub}:{rcub}etasp5{dollar}-fulvalene){dollar}rm Mosb2(CO)sb6.{dollar} The results were consistent with a mechanism (Eq 20) involving radica... |
