Dataset Information

Re(V) and Re(III) complexes with sal2phen and triphenylphosphine: rearrangement, oxidation and reduction.

ABSTRACT: Reactions of Re(V), tetradentate Schiff base complexes with tertiary phosphines have previously yielded both rearranged Re(V) and reduced Re(III) complexes. To further understand this chemistry, the rigid diiminediphenol (N(2)O(2)) Schiff base ligand sal(2)phen (N,N'-o-phenylenebis(salicylaldimine)) was reacted with (n-Bu(4)N)[ReOCl(4)] to yield trans-[ReOCl(sal(2)phen)] (1). On reaction with triphenylphosphine (PPh(3)), a rearranged Re(V) product cis-[ReO(PPh(3))(sal(2)phen*)]PF(6) (2), in which one of the imines was reduced to an amine during the reaction, and the reduced Re(III) products trans-[ReCl(PPh(3))(sal(2)phen)] (4) and trans-[Re(PPh(3))(2)(sal(2)phen)](+) (5) were isolated. Reaction of sal(2)phen with [ReCl(3)(PPh(3))(2)(CH(3)CN)] resulted in the isolation of [ReCl(2)(PPh(3))(2)(salphen)] (3). The compounds were characterized using standard spectroscopic methods, elemental analyses and single crystal X-ray crystallography.

SUBMITTER: Lane SR

PROVIDER: S-EPMC3059235 | biostudies-literature | 2011 Jan

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Re(V) and Re(III) complexes with sal2phen and triphenylphosphine: rearrangement, oxidation and reduction.

Lane Stephanie Renee SR Sisay Nebiat N Carney Brett B Dannoon Shorouk S Williams Stephen S Engelbrecht Hendrik Petrus HP Barnes Charles Leslie CL Jurisson Silvia Sabine SS

Dalton transactions (Cambridge, England : 2003) 20101115 1

Reactions of Re(V), tetradentate Schiff base complexes with tertiary phosphines have previously yielded both rearranged Re(V) and reduced Re(III) complexes. To further understand this chemistry, the rigid diiminediphenol (N(2)O(2)) Schiff base ligand sal(2)phen (N,N'-o-phenylenebis(salicylaldimine)) was reacted with (n-Bu(4)N)[ReOCl(4)] to yield trans-[ReOCl(sal(2)phen)] (1). On reaction with triphenylphosphine (PPh(3)), a rearranged Re(V) product cis-[ReO(PPh(3))(sal(2)phen*)]PF(6) (2), in whic ...[more]

PMID: 21079821

Similar Datasets

Project description:The first use of a dinuclear UIII/UIII complex in the activation of small molecules is reported. The octadentate Schiff-base pyrrole, anthracene-hinged 'Pacman' ligand LA combines two strongly reducing UIII centres and three borohydride ligands in [M(THF)4][{U(BH4)}2(?-BH4)(LA)(THF)2] 1-M, (M = Li, Na, K). The two borohydride ligands bound to uranium outside the macrocyclic cleft are readily substituted by aryloxide ligands, resulting in a single, weakly-bound, encapsulated endo group 1 metal borohydride bridging the two UIII centres in [{U(OAr)}2(?-MBH4)(LA)(THF)2] 2-M (OAr = OC6H2t Bu3-2,4,6, M = Na, K). X-ray crystallographic analysis shows that, for 2-K, in addition to the endo-BH4 ligand the potassium counter-cation is also incorporated into the cleft through ?5-interactions with the pyrrolides instead of extraneous donor solvent. As such, 2-K has a significantly higher solubility in non-polar solvents and a wider U-U separation compared to the 'ate' complex 1. The cooperative reducing capability of the two UIII centres now enforced by the large and relatively flexible macrocycle is compared for the two complexes, recognising that the borohydrides can provide additional reducing capability, and that the aryloxide-capped 2-K is constrained to reactions within the cleft. The reaction between 1-Na and S8 affords an insoluble, presumably polymeric paramagnetic complex with bridging uranium sulfides, while that with CS2 results in oxidation of each UIII to the notably high UV oxidation state, forming the unusual trithiocarbonate (CS3)2- as a ligand in [{U(CS3)}2(?-?2:?2-CS3)(LA)] (4). The reaction between 2-K and S8 results in quantitative substitution of the endo-KBH4 by a bridging persulfido (S2)2- group and oxidation of each UIII to UIV, yielding [{U(OAr)}2(?-?2:?2-S2)(LA)] (5). The reaction of 2-K with CS2 affords a thermally unstable adduct which is tentatively assigned as containing a carbon disulfido (CS2)2- ligand bridging the two U centres (6a), but only the mono-bridged sulfido (S)2- complex [{U(OAr)}2(?-S)(LA)] (6) is isolated. The persulfido complex (5) can also be synthesised from the mono-bridged sulfido complex (6) by the addition of another equivalent of sulfur.

Project description:To evaluate the microbial populations involved in the reduction of Fe(III) in an acidic, iron-rich sediment, the anaerobic flow of supplemental carbon and reductant was evaluated in sediment microcosms at the in situ temperature of 12 degrees C. Supplemental glucose and cellobiose stimulated the formation of Fe(II); 42 and 21% of the reducing equivalents that were theoretically obtained from glucose and cellobiose, respectively, were recovered in Fe(II). Likewise, supplemental H(2) was consumed by acidic sediments and yielded additional amounts of Fe(II) in a ratio of approximately 1:2. In contrast, supplemental lactate did not stimulate the formation of Fe(II). Supplemental acetate was not consumed and inhibited the formation of Fe(II). Most-probable-number estimates demonstrated that glucose-utilizing acidophilic Fe(III)-reducing bacteria approximated to 1% of the total direct counts of 4', 6-diamidino-2-phenylindole-stained bacteria. From the highest growth-positive dilution of the most-probable-number series at pH 2. 3 supplemented with glucose, an isolate, JF-5, that could dissimilate Fe(III) was obtained. JF-5 was an acidophilic, gram-negative, facultative anaerobe that completely oxidized the following substrates via the dissimilation of Fe(III): glucose, fructose, xylose, ethanol, glycerol, malate, glutamate, fumarate, citrate, succinate, and H(2). Growth and the reduction of Fe(III) did not occur in the presence of acetate. Cells of JF-5 grown under Fe(III)-reducing conditions formed blebs, i.e., protrusions that were still in contact with the cytoplasmic membrane. Analysis of the 16S rRNA gene sequence of JF-5 demonstrated that it was closely related to an Australian isolate of Acidiphilium cryptum (99.6% sequence similarity), an organism not previously shown to couple the complete oxidation of sugars to the reduction of Fe(III). These collective results indicate that the in situ reduction of Fe(III) in acidic sediments can be mediated by heterotrophic Acidiphilium species that are capable of coupling the reduction of Fe(III) to the complete oxidation of a large variety of substrates including glucose and H(2).

Dataset Information

Re(V) and Re(III) complexes with sal2phen and triphenylphosphine: rearrangement, oxidation and reduction.

Publications

Re(V) and Re(III) complexes with sal2phen and triphenylphosphine: rearrangement, oxidation and reduction.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets