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The E1/2 potential associated with reduction of the linearly-functionalized 6,6′-biazulenic scaffold is accurately correlated to the combined σp Hammett parameters of the substituents over >600 mV range. X-ray crystallographic analysis of the 2,2′-dichloro-substituted derivative revealed unexpectedly short C–Cl bond distances, along with other metric changes, suggesting a non-trivial cycloheptafulvalene-like structural contribution. [ABSTRACT FROM AUTHOR]

The synthesis of the air- and thermally-stable 2,6 diisocyano-1,3-diethoxycarbonylazulene linker from 2-amino-1,3-diethoxycarbonylazulene in 57% cumulative yield is reported. A crystallographically characterized 6-isocyano-2-diisocyanoazulene derivative was employed to access mono- and heterobimetallic complexes of the 2,6-diisocyanoazulene scaffolds with controlled orientation of the azulene dipole.

Research has been conducted on the amodiximates. The strategy developed for the amidoximate coordination via the oximato O and amido N atoms is described.

The main step in accessing the title species, the first nonbenzenoid diisocyanobiaryl, has involved the homocoupling of a 6-bromoazulene derivative. The shifts in energies of the transitions for a series of related 6,6'-biazulenyl derivatives have correlated with the [e.sup.-]-donating/-withdrawing strength of their 2,2'-substituents but have followed opposite trends.

A one-pot transformation of bis(2-isocyano-3-methylphenyl)ethane has afforded gram quantities of 8,16,24,32-tetraisocyano[2.2.2.2]metacyclophane. Isocyanide groups have functioned as effective two-atom long anchors for self-assembling stable monolayers of cyclophanes on metallic gold.

Reduction of M[(CNXyl).sub6]l by cesium graphite gave the respective Cs[M[(CNXyl).sub.6], which are structurally defined and described the first isolable homoleptic isocyanidemetalates for second or third row transition metals. Results reveal that nitrosylation of[Ta[(CNXyl).sub.6].sup-] affords a rare example of mononitrosyl tantalum complex, Ta[(CNXyl).sub.5]NO.

A biosynthetic and enzymatic approach for the efficient preparation of (super 13)C-labeled alpha-verdoheme, which facilitates the (super 13)C NMR spectroscopic characterization of the elusive verdoheme-HO complex is reported. The (super 13)C NMR evidence indicates that Fe(super 11)-verdoheme in HO is six-coordinate and diamagnetic (S = 0), a finding that underscores the chemical difference between ferrous heme and ferrous verdoheme.

The initial member of the isocyanoazulene family, 6- isocyanoazulene, and its binary complexes [Cr(CN(super 6)AZ)6](super 0/1+) is described. The pi-accepting potential as a ligand is demonstrated for 6-isocyanoazulene.

A hydrocarbonation of allenes catalyzed by palladium is developed, which meets the goal of an atom economic process. The process is a simple addition where anything else is needed only catalytically and would increase significantly in its power, if it could be performed asymmetrically.

The design and synthesis of a molecular umbrella, derived from three biogenic precursors, cholic acid, spermidine and arginine is reported. The molecular umbrella readily transports adenosine 5-triphosphate, across phospho-lipid layers made from 1-palmitoyl-2-oleyol-sn-glycero-3-phos-phocoline and 1-palmitoyl-2-oleyol-sn-glycero-3-phos-phatidylglycerol.

A molecular dynamics simulation of rhodopsin in a realistic environment, with polyunsaturated lipids similar to retinal membranes is described. The atomic-level picture that emerges from the simulation reveals that rhodopsin has the ability to organize the lipid solvation structure through preferential interactions with the polyunsaturated docosohexaenoic acid.

The first binary complexes of isocyanoferrocene are reported. It is demonstrated that the donor/acceptor ratio of the CNFc ligand is similar to those of aryl isocyanides but quite different from those of alkyl isocyanides.

A study reports on the successful synthesis of the first binary, homoleptic niobium and tantalum isocyanides and related novel compounds. It is hoped that experimental results will spur the development of the existing and quite limited isocyanide chemistry of niobium and tantalum. Attempts to isolate the niobium and tantalum analogues of V(CNXyl)63 and extension of this study to the group four elements are being conducted. Experimental methods and findings are presented.

A study was conducted on the isolation, syntheses and structural characterization of hexakis(2,6-dimethylphenyl isocyanide)vanadium(I, O, - I) and a monocation. Spectroscopic and magnetic properties of the vanadium homoleptic isocyanide complexes verify that they are mononuclear six-coordinate complexes with specific low spin vanadium values. Results support assumptions that n1-RNC ligands become increasingly bent as electrons in the metal center are enhanced.

The highly reduced carbonylmetalate, (Nb(CO)5)(super 3-),(super 10), was synthesized, characterized and its chemical properties determined. Sodium naphthalene- or anthracene-mediated reductive carbonylations of NbCl4(THF)2 afforded (Nb(CO)6)- in 60% to 70% yields, the highest reported so far for syntheses performed at atmospheric pressure. Corresponding reactions undertaken with PF3 gave the first conventional pathway to (Nb(PF3)6)-. The reduction of 99% 13C enriched (nb(13CO)6)- by sodium in liquid ammonia afforded the super-reduced species (Nb(13CO)5)(super 3-).

Treatment of [M(CO)6]-, M = Nb, Ta, with Ag+, I2 or NO+ in the presence of CNXyI provided [M(CNXyI)7]+, M(CNXyI)6I, or c/s-[M(CNXyI)4(NO)2]+, which are isocyanide analogues of the unknown carbonyl complexes [M(CO)7]+, M(CO)6I, or cis-[M(CO)4(NO)2]+, respectively. Reduction of M(CNXyI)6I by cesium graphite gave the respective Cs[M(CNXyI)6], which have been structurally characterized and represent the first isolable homoleptic isocyanidemetalates for second or third row transition metals. Nitrosylation of [Ta(CNXyI)6] affords a rare example of a mononitrosyl tantalum complex, Ta(CNXyI)5NO, which is an isocyanide analogue of the unknown Ta(CO)5NO. This study emphasizes, inter alia, the remarkable versatility of the CNXyI ligand compared to CO in stabilizing various electronic environments at heavier group 5 metal centers. [ABSTRACT FROM AUTHOR]