Metathesis chemistry of inorganic cumulenes driven by B-O bond formation.

The reaction chemistry of an unprecedented 'inorganic cumulene' - featuring a five-atom BNBNB chain - towards C[double bond, length as m-dash]O (and related) multiple bonds is disclosed. In marked contrast to related all-carbon systems, the intrinsic polarity of the BNBNB chain (featuring electron-rich nitrogen and electron-deficient boron centres) enables metathesis chemistry with electrophilic heteroallenes such as CO and with organic carbonyl compounds. Transfer of the borylimide unit to [CO], [CS], [PP{(NDippCH)}] and [C(H)Ph] moieties generates (boryl)N[double bond, length as m-dash]C[double bond, length as m-dash]X systems (X = O, S, PP{(NDippCH)}, C(H)Ph), driven thermodynamically by B-O bond formation.

A Crystalline Unsupported Phosphagallene and Phosphaindene.

The synthesis and isolation of TerP═GaTer and TerP═InTer (Ter = 2,6-Dipp-CH; Dipp = 2,6-diisopropylphenyl) is reported. These compounds feature unsupported P═Ga and P═In double bonds and two-coordinate triel element centers. Key to the stabilization of such compounds is the steric bulk of the terphenyl substituents, which serve to shield the highly reactive P═E bonds (E = Ga, In) and prevent further aggregation.

Cyaphide group transfer from covalent metal complexes: contrasting pathways to transmetallation.

We describe two contrasting transmetallation reactions between the gold(I) cyaphide complex, Au(IDipp)(CP) (IDipp = 1,3-bis(2,6-diisopropylphenyl)imidazol-2-ylidene), and low oxidation state main-group and transition-metal complexes. The reactivity observed highlights the pseudo-halide character of the cyaphide ion.

Respiratory symptoms among e-cigarette users without an established smoking history in the VERITAS cohort.

Prior research on e-cigarettes' health impacts is inconclusive due to confounding by previous tobacco smoking. Studies of e-cigarette use among people without an established smoking history are informative for this question. A cross-sectional survey was administered across six geopolitical world regions to adults aged 18+ without a history of established cigarette smoking or regular use of other nicotine/tobacco products.

Syntheses, Geometric and Electronic Structures of Inorganic Cumulenes.

Molecular chains of two-coordinate carbon atoms (cumulenes) have long been targeted, due to interest in the electronic structure and applications of extended π-systems, and their relationship to the carbon allotrope, carbyne. While formal (isoelectronic) B═N for C═C substitution has been employed in two-dimensional (2-D) materials, unsaturated one-dimensional all-inorganic "molecular wires" are unknown. Here, we report high-yielding synthetic approaches to heterocumulenes containing a five-atom BNBNB chain, the geometric structure of which can be modified by choice of end group.