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Formal addition of diazomethane's terminal nitrogen atom to the 9,10-positions of anthracene yields H 2 CN 2 A ( 1 , A = C 14 H 10 or anthracene). The synthesis of this hydrazone is reported from Carpino's hydrazine H 2 N 2 A through treatment with paraformaldehyde. Compound 1 has been found to be an easy-to-handle solid that does not exhibit dangerous heat or shock sensitivity. Effective umpolung of the diazomethane unit imbues 1 with electrophilicity at the methylene carbon center. Its reactivity with nucleophiles such as H 2 CPPh 3 and N-heterocyclic carbenes is exploited for CC bond formation with elimination of dinitrogen and anthracene. Similarly, 1 is demonstrated to deliver methylene to a nucleophilic singlet d 2 transition metal center, W(ODipp) 4 ( 2 ), to generate the robust methylidene complex [ 2 CH 2 ]. This behavior is contrasted with that of the Wittig reagent H 2 CPPh 3 , a more traditional and Brønsted basic methylene source that upon exposure to 2 contrastingly forms the methylidyne salt [MePPh 3 ][ 2 CH]. 

Tungsten( iv ) tetrakis(2,6-diisopropylphenoxide) ( 1 ) has been demonstrated to be a competent platform for decarbonylative formation of anionic terminal pnictide complexes upon treatment with pnictaethynolate anions: cyanate, 2-phosphaethynolate, and 2-arsaethynolate. These transformations constitute the first examples of terminal phosphide and arsenide complex formation at a transition metal center from OCP − and OCAs − , respectively. The phosphide and arsenide complexes are also the first to be isolated in a tetragonal, all-oxygen ligand environment. The scalar NMR coupling constants between tungsten-183 and nitrogen-15 or phosphorus-31 have been measured and contextualized using natural bond orbital (NBO) methods in terms of s orbital character in the σ bonding orbital and pnictide lone pair. 

Targeted as an example of a compound composed of a carbon atom together with two stable neutral leaving groups, 7-isocyano-7-azadibenzonorbornadiene, CN 2 A ( 1 , A = C 14 H 10 or anthracene) has been synthesized and spectroscopically and structurally characterized. The terminal C atom of 1 can be transferred: mesityl nitrile oxide reacts with 1 to produce carbon monoxide, likely via intermediacy of the N -isocyanate OCN 2 A . Reaction of 1 with [RuCl 2 (CO)(PCy 3 ) 2 ] leads to [RuCl 2 (CO)( 1 )(PCy 3 ) 2 ] which decomposes unselectively: in the product mixture, the carbide complex [RuCl 2 (C)(PCy 3 ) 2 ] was detected. Upon heating in the solid state or in solution, 1 decomposes to A , N 2 and cyanogen (C 2 N 2 ) as substantiated using molecular beam mass spectrometry, IR and NMR spectroscopy techniques.