Because only 0.01% of prokaryotic genospecies can be cultured and in situ observations are often impracticable, culture-independent methods are required to understand microbial life and harness potential applications of microbes. Here, we report a methodology for the production of proteins with desired functions based on single amplified genomes (SAGs) from unculturable species. We use this method to resurrect an alcohol dehydrogenase (ADH/D1) from an uncharacterized halo-thermophilic archaeon collected from a brine pool at the bottom of the Red Sea. Our crystal structure of 5,6-dihydroxy NADPH-bound ADH/D1 combined with biochemical analyses reveal the molecular features of its halo-thermophily, its unique habitat adaptations, and its possible reaction mechanism for atypical oxygen activation. Our strategy offers a general guide for using SAGs as a source for scientific and industrial investigations of "microbial dark matter."

The single-site silica-supported group IV metal amido complex [Ti(NMe 2 ) 4 ] gives the tris(amido)-supported fragment [(Si−O−)Ti(−NMe 2 ) 3 ], which transforms into a three-membered metallacycle (called a metallaaziridine) by an α-H transfer between two amido ligands. When the three-membered metallacycle reacts with 1-octene, it gives a five-membered metallacycle by insertion of the double bond into the M−C bond of the metallaziridine. These two metallacycles, key intermediates in the catalytic cycle of the hydroaminoalkylation of terminal olefins, were isolated and fully characterized following the surface organometallic chemistry (SOMC) concept and procedures. This paper shows that surface organometallic chemistry can be used to identify and fully characterize three-and five-membered metallacycles of Ti in the hydroaminoalkylation of olefins. Article pubs.acs.org/Organometallics

Metallo-carbynes grafted on mesoporous fibrous silica are active towards alkane metathesis. We are comparing the activity of well-defined grafted pre-catalysts (� SiÀ OÀ)W(� CCMe 3)(iÀ CH 2 CMe 3) 2 , (� SiiÀ OiÀ)W(� CH)(iÀ CH 3) 2 and (� SiiÀ OiÀ) Mo(� CCMe 3)(iÀ CH 2 CMe 3) 2 for Ring Opening Metathesis Polymerization of cyclo-octene and metathesis of cyclo-octane. This comparison is because olefins are assumed to be intermediate products in alkane metathesis. The three pre-catalysts are active in cyclo-octane metathesis, and give the higher, and lower cyclic homologues. However, with cyclo-octene the three catalysts give polyoctenamer by classical ROMP. It is assumed that the metallo-carbynes react differently towards cycloalkanes and cyclo-olefins. In one case, with cyclo-alkanes they give a metallo-carbene alkyl and in the other case with cycloolefins they give a bis-carbene. Scheme 2. Coordination of the internal cis double bond with respect to the propagating metallocarbene. This leads to degenerate cis trans isomerization for complexes 1 (left), and 2 and 3 (right) of the acyclic double bonds in the polymer chain. Molybdenum has been removed for clarity. Scheme 3. CÀ H addition on metallo-carbyne bond leading to the metallocarbene-hydride.

Multi-gram amounts of halogen-free lipophilic aluminate salts have been prepared, featuring two sterically demanding chelating ligands derived from a methane-2,2´-bisphenolate. The ligand is prepared by condensation of two equivalents of 2,4-di-tert-butylphenol with acetone induced by boron fluoride etherate. The C 2 -symmetry of this "almebate" anion implies helical chirality. Substantial steric shielding of the aluminate core results in high stability towards aqueous bases. Almebate salts hydrolyze in aqueous acetic acid at room temperature within days. Tetraphenylphosphonium and tetrabutylammonium salts have been prepared by salt metatheses. Sodium almebate can be activated thermally, generating electrophilic sodium(I) with a low coordination number. It eliminates chloride ligands from an N-heterocyclic carbene gold chloride complex, proven by a single-crystal X-ray diffraction study. The barrier of molecular racemization by a degenerate rearrangement of the intrinsically chiral almebate anion in acetone has been determined to be G ‡ 53.6 ± 2 kJ mol -1 from four 1 H NMR coalescence phenomena (500 MHz; 258 K, 273 K, 283 K, 290 K).

Tungsten-hydrides supported on oxide supports are unique catalysts regarding the direct transformation of ethylene to propylene, alkane metathesis, and the low-temperature hydrogenolysis of waxes to lower molecular paraffins. The number of hydrides coordinated to the tungsten center and their structure on the siliceous support with very high surface silica (KCC-1) is unknown. KCC-1(700) silica of extremely high surface area allows for a high tungsten metal loading of 14 wt %. We show here the full characterization of supported tungsten bis- and tris-hydrides, which, after reaction with N2O gas, yield well-defined tungsten bis- and tris-hydroxide species on KCC-1(700). The obtained tungsten-hydroxide species are perfectly suitable for a detailed NMR study. The obtained tungsten hydroxo complexes are proven to be a tungsten bis-hydroxo and tungsten tris-hydroxo species. This analysis supports the conclusion that supported tungsten-hydride complexes coexist on the support as bis-hydride and tris-hydride species. They are, respectively, in close proximity to the silicon bis-hydride and the silicon mono-hydride. This proximity is explained by the mechanism of the formation of tungsten-hydride on the silica surface.