Tellurolate: an effective Te-atom transfer reagent to prepare the triad of group 5 metal bis(tellurides).

We show in this work how lithium tellurolate Li(X)TeCHSiMe (X = THF, = 1, 1; X = 12--4, = 2, 2), can serve as an effective Te-atom transfer reagent to all group 5 transition metal halide precursors irrespective of the oxidation state. Mononuclear and bis(telluride) complexes, namely (PNP)M(Te) (M = V; Nb, 3; Ta, 4; PNP = N[2-PPr-4-methylphenyl]), are reported herein including structural and spectroscopic data. Whereas the known complex (PNP)V(Te) can be readily prepared from the trivalent precursor (PNP)VCl, two equiv.

Accelerating σ-Bond Metathesis at Sn(II) Centers.

Molecular main-group hydride catalysts are attractive as cheap and Earth-abundant alternatives to transition-metal analogues. In the case of the latter, specific steric and electronic tuning of the metal center through ligand choice has enabled the iterative and rational development of superior catalysts. Analogously, a deeper understanding of electronic structure-activity relationships for molecular main-group hydrides should facilitate the development of superior main-group hydride catalysts.

The role of DNA methylation on gene expression in the vertebrae of ancestrally benzo[a]pyrene exposed F1 and F3 male medaka.

Benzo[a]pyrene (BaP) is ubiquitously present in the aquatic environment and has been identified as a bone toxicant. Previous studies have demonstrated that ancestral BaP exposure can cause transgenerational bone deformities in fish. Transgenerational effects are thought to be caused by heritable epigenetic changes, such as DNA methylation, histone modification, and non-coding RNAs.

Transgenerational bone toxicity in F3 medaka (Oryzias latipes) induced by ancestral benzo[a]pyrene exposure: Cellular and transcriptomic insights.

Benzo[a]pyrene (BaP), a ubiquitous pollutant, raises environmental health concerns due to induction of bone toxicity in the unexposed offspring. Exposure of F0 ancestor medaka (Oryzias latipes) to 1 µg/L BaP for 21 days causes reduced vertebral bone thickness in the unexposed F3 male offspring. To reveal the inherited modifications, osteoblast (OB) abundance and molecular signaling pathways of transgenerational BaP-induced bone thinning were assessed.

Direct Reduction of NO to NO by a Mononuclear Nonheme Thiolate Ligated Iron(II) Complex via Formation of a Metastable {FeNO} Complex.

Addition of NO to a nonheme dithiolate-ligated iron(II) complex, Fe(MeTACN)(SSiMe) (), results in the generation of NO. Low-temperature spectroscopic studies reveal a metastable six-coordinate {FeNO} intermediate ( = 3/2) that was trapped at -135 °C and was characterized by low-temperature UV-vis, resonance Raman, EPR, Mössbauer, XAS, and DFT studies. Thermal decay of the {FeNO} species leads to the evolution of NO, providing a rare example of a mononuclear thiolate-ligated {FeNO} that mediates NO reduction to NO without the requirement of any exogenous electron or proton sources.

Heterobimetallic μ-halocarbyne complexes.

The halocarbyne complexes [M(CX)(CO)(Tp*)] (M = Mo, W; X = Cl, Br; Tp* = hydrotris(dimethylpyrazolyl)borate) react with [AuCl(SMe)], [Pt(η-HCCH)(PPh)] or [Pt(η-nbe)] (nbe = norbornene) to furnish rare examples of μ-halocarbyne complexes [MAu(μ-CX)Cl(CO)(Tp*)], [MPt(μ-CCl)(CO)(PPh)(Tp*)] and [WPt(μ-CCl)(CO)(Tp*)]. The complex [WPt(μ-CCl)(CO)(PPh)(Tp*)] spontaneously rearranges to the μ-carbido complex [WPt(μ-C)Cl(CO)(PPh)(Tp*)] during silica-gel chromatography. One phosphine ligand of [WPt(μ-CCl)(CO)(PPh)(Tp*)] is readily substituted by CO to afford [WPt(μ-CCl)(CO)(PPh)(Tp*)].

Stereoselective insertion of cyclopropenes into Mg-Mg bonds.

The reaction of cyclopropenes with compounds containing Mg-Mg bonds is reported. 1,2-Dimagnesiation occurs exclusively by -addition to the least hindered face of the alkene forming a single diastereomeric product. DFT calculations support a concerted and stereoselective mechanism.

Functionalization and Hydrogenation of Carbon Chains Derived from CO.

Selective reactions that combine H , CO and organic electrophiles (aldehyde, ketones, isocyanide) to form hydrogenated C and C carbon chains are reported. These reactions proceed by CO homologation mediated by [W(CO) ] and an aluminum(I) reductant, followed by functionalization and hydrogenation of the chain ends. A combination of kinetics (rates, KIEs) and DFT calculations has been used to gain insight into a key step which involves hydrogenation of a metallocarbene intermediate.

Reactions of aluminium(i) with transition metal carbonyls: scope, mechanism and selectivity of CO homologation.

Over the past few decades, numerous model systems have been discovered that create carbon-carbon bonds from CO. These reactions are of potential relevance to the Fischer-Tropsch process, a technology that converts syngas (H/CO) into mixtures of hydrocarbons. In this paper, a homogeneous model system that constructs carbon chains from CO is reported.

1 row transition metal aluminylene complexes: preparation, properties and bonding analysis.

The synthesis and spectroscopic characterisation of eight new first-row transition metal (M = Cr, Mn, Fe, Co, Cu) aluminylene complexes is reported. DFT and ab initio calculations have been used to provide detailed insight into the metal-metal bond. The σ-donation and π-backdonation properties of the aluminylene ligand are evaluated via NBO and ETS-NOCV calculations.

Group 11 Borataalkene Complexes: Models for Alkene Activation.

A series of linear late transition metal (M=Cu, Ag, Au and Zn) complexes featuring a side-on [B=C] containing ligand have been isolated and characterised. The [B=C] moiety is isoelectronic with the C=C system of an alkene. Comparison across the series shows that in the solid-state, deviation between the η and η coordination mode occurs.

Chemoselective C-C σ-Bond Activation of the Most Stable Ring in Biphenylene*.

The chemoselective cleavage of a six-membered aromatic ring in biphenylene is reported using an aluminum(I) complex. This type of selectivity is unprecedented. In every example of transition metal mediated C-C σ-bond activation reported to date, the reaction occurs at the central four-membered ring of biphenylene.

Indication of Electromagnetic Field Exposure via RBF-SVM Using Time-Series Features of Zebrafish Locomotion.

This paper introduces a novel model based on support vector machine with radial basis function kernel (RBF-SVM) using time-series features of zebrafish () locomotion exposed to different electromagnetic fields (EMFs) to indicate the corresponding EMF exposure. A group of 14 adult zebrafish was randomly divided into two groups, 7 in each group; the fish of each group have the novel tank test under a sham or real magnetic exposure of 6.78 MHz and about 1 A/m.

Multigenerational Impacts of Benzo[]pyrene on Bone Modeling and Remodeling in Medaka ().

Ancestral benzo[]pyrene (BaP) (1 μg/L, 21 days) exposure has previously been shown to cause skeletal deformities in medaka () larvae in the F1-F3 generation. However, when and how this deformity is induced during bone development remain to be elucidated. The :nlGFP/:mCherry double transgenic medaka model was employed to determine the temporal and spatial changes of :nlGFP- positive osteochondral progenitor cells (OPCs) and :mCherry-positive premature osteoblasts (POBs) [8 days postfertilization (dpf)-31 dpf] in combination with changes in bone mineralization at the tissue level.

Activation and Functionalization of C-C σ Bonds of Alkylidene Cyclopropanes at Main Group Centers.

Aluminum(I) and magnesium(I) compounds are reported for the C-C σ-bond activation of strained alkylidene cyclopropanes. These reactions result in the formal addition of the C-C σ bond to the main group center either at a single site (Al) or across a metal-metal bond (Mg-Mg). Mechanistic studies suggest that rather than occurring by a concerted oxidative addition, these reactions involve stepwise processes in which substrate binding to the main group metal acts as a precursor to α- or β-alkyl migration steps that break the C-C σ bond.

Cooperative strategies for CO homologation.

Recent approaches in which at least two metal or main-group centres are involved in the homologation of CO are reviewed. We have characterised the strategies into three broad areas: (i) the reductive homologation of atmospheric CO at a metal or main group centre (ii) the reductive homologation of metal-carbonyl CO units and (iii) reductive homologation of CO with M-M, B-Li, Si[double bond, length as m-dash]Si, and B[triple bond, length as m-dash]B bonds.

Reactions of an Aluminum(I) Reagent with 1,2-, 1,3-, and 1,5-Dienes: Dearomatization, Reversibility, and a Pericyclic Mechanism.

Addition of the aluminum(I) reagent [{(ArNCMe)CH}Al] (Ar = 2,6-di-iso-propylphenyl) to a series of cyclic and acyclic 1,2-, 1,3-, and 1,5-dienes is reported. In the case of 1,3-dienes, the reaction occurs by a pericyclic reaction mechanism, specifically a cheletropic cycloaddition, to form aluminocyclopentene-containing products. This mechanism has been examined by stereochemical experiments and DFT calculations.

Reversible insertion of CO into an aluminium-carbon bond.

A [2.2.1] aluminium metallobicycle is capable of reversibly inserting CO to form a [2.

Carbon Chain Growth by Sequential Reactions of CO and CO with [W(CO)] and an Aluminum(I) Reductant.

The formation of carbon chains by the coupling of CO ( x = 1 or 2) units on transition metals is a fundamental step relevant to Fischer-Tropsch catalysis. Fischer-Tropsch catalysis produces energy dense liquid hydrocarbons from synthesis gas (CO and H) and has been a mainstay of the energy economy since its discovery nearly a century ago. Despite detailed studies aimed at elucidating the steps of catalysis, experimental evidence for chain growth (C → C ; n ≥ 2) from the coupling of CO units on metal complexes is, to the best of our knowledge, unprecedented.

An unusual alkylidyne homologation.

The reaction of [W([triple bond, length as m-dash]CH)Br(CO)(dcpe)] (dcpe = 1,2-bis(dicyclohexylphosphino)ethane) with BuLi and SiCl affords the trichlorosilyl ligated neopentylidyne complex [W([triple bond, length as m-dash]CBu)(SiCl)(CO)(dcpe)]. This slowly reacts with HO to afford [W([triple bond, length as m-dash]CCHBu)Cl(dcpe)] and ultimately HC[double bond, length as m-dash]CHBu via an unprecedented alkylidyne homologation in which coordinated CO is the source of the additional carbon atom with potential relevance to the Fischer-Tropsch process.

Transcriptomic analysis reveals transgenerational effect of hypoxia on the neural control of testicular functions.

There are over 400 hypoxic zones in the ocean worldwide. Both laboratory and field studies have shown that hypoxia causes endocrine disruption and reproductive impairments in vertebrates. More importantly, our recent study discovered that parental (F0) hypoxia exposure resulted in the transgenerational impairment of sperm quality in the F2 generation through the epigenetic regulation of germ cells.

An anionic nucleophilic d carbyne complex.

The reaction of the methylidyne complex [W([triple bond, length as m-dash]CH)Br(CO)(dcpe)] (dcpe = 1,2-bis(dicyclohexylphosphino)ethane) with BuLi affords the intermediate anionic neopentylidyne complex Li[W([triple bond, length as m-dash]CBu)(CO)(dcpe)] which acts as a metal-based nucleophile towards BuCl, BuBr, PhE (E = S, Se, Te) and ClSnMe to afford the new carbyne complexes [W([triple bond, length as m-dash]CBu)(X)(CO)(dcpe)] (X = Cl, Br, EPh, SnMe).

High oxidation state bromocarbyne complexes.

Bromination of the carbyne complexes [W([triple bond, length as m-dash]CR)Br(CO)(dcpe)] (R = Ph, SiPh; dcpe = 1,2-bis(dicyclohexylphosphino)ethane) provides high oxidation state derivatives [W([triple bond, length as m-dash]CPh)Br(dcpe)] and [W([triple bond, length as m-dash]CBr)Br(dcpe)], the latter via an unprecedented bromodesilylation process.

Potential mechanisms underlying estrogen-induced expression of the molluscan estrogen receptor (ER) gene.

In vertebrates, estrogens and estrogen mimicking chemicals modulate gene expression mainly through a genomic pathway mediated by the estrogen receptors (ERs). Although the existence of an ER orthologue in the mollusc genome has been known for some time, its role in estrogen signalling has yet to be deciphered. This is largely due to its constitutive (ligand-independent) activation and a limited mechanistic understanding of its regulation.