The facile synthesis of a stable and isolable compound with a fluoroalkynyl group, M-C≡CF, is reported. Reaction of [Ru(C≡CH)(η -C Me )(dppe)] with an electrophilic fluorinating agent (NFSI) results in the formation of the fluorovinylidene complex [Ru(=C=CHF)(η -C Me )(dppe)][N(SO Ph) ]. Subsequent deprotonation with LiN(SiMe ) affords the fluoroalkynyl complex [Ru(C≡CF)(η -C Me )(dppe)]. In marked contrast to the rare and highly reactive examples of fluoroalkynes that have been reported previously, this compound can be readily isolated and structurally characterized. This has allowed the structure and bonding in the CCF motif to be explored. Further electrophilic fluorination of this species yields the difluorovinylidene complex [Ru(C=CF )(η -C Me )(dppe)][N(SO Ph) ].

The solution and gas-phase dissociative photochemistry of two ruthenium half-sandwich complexes are analysed with electrospray ionisation mass spectrometry in a novel instrument.

Metal vinylidene complexes are widely encountered, or postulated, as intermediates in a range of important metal-mediated transformations of alkynes. However, fluorovinylidene complexes have rarely been described and their reactivity is largely unexplored. By making use of the novel outer-sphere electrophilic fluorination (OSEF) strategy we have developed a rapid, robust and convenient method for the preparation of fluorovinylidene and trifluoromethylvinylidene ruthenium complexes from non-fluorinated alkynes. Spectroscopic investigations (NMR and UV/Vis), coupled with TD-DFT studies, show that fluorine incorporation results in significant changes to the electronic structure of the vinylidene ligand. The reactivity of fluorovinylidene complexes shows many similarities to non-fluorinated analogues, but also some interesting differences, including a propensity to undergo unexpected C-F bond cleavage reactions. Heating fluorovinylidene complex [Ru(η(5)-C5H5)(PPh3)2(C[double bond, length as m-dash]C{F}R)][BF4] led to C-H activation of a PPh3 ligand to form an orthometallated fluorovinylphosphonium ligand. Reaction with pyridine led to nucleophilic attack at the metal-bound carbon atom of the vinylidene to form a vinyl pyridinium species, which undergoes both C-H and C-F activation to give a novel pyridylidene complex. Addition of water, in the presence of chloride, leads to anti-Markovnikov hydration of a fluorovinylidene complex to form an α-fluoroaldehyde, which slowly rearranges to its acyl fluoride isomer. Therefore, fluorovinylidenes ligands may be viewed as synthetic equivalents of 1-fluoroalkynes providing access to reactivity not possible by other routes.

The speciation, conformation, and reactivity of transition metal complexes at the gas−liquid interface are poorly understood, yet the potential is high for observing chemistry unique to this anisotropic interface and leveraging interfacial structure to control the state and environment of the complex. If transition metal complexes can be designed to populate a liquid−vacuum interface preferentially, then it may be possible to explore catalytic behavior by delivering reactants to the interface with a molecular beam and monitoring the scattering dynamics of reaction products to obtain detailed information on the reaction mechanism. In this initial experimental study, we have used reactive-atom scattering with a hyperthermal F-atom probe, X-ray photoelectron spectroscopy, and time-of-flight secondary ion mass spectrometry to explore the interfacial composition and structure of a ∼2 mg/mL solution of [RuCl 2 (p-cymene)P(C 8 H 17 ) 3 ] in perdeuterated 1-ethyl-3-methylimidazolium bis-(trifluoromethylsulfonyl)imide (d 11 -[C 2 mim][Tf 2 N]). These data provide strong evidence that a Ru complex is present at the extreme liquid−vacuum interface with a number density that is higher than expected from the bulk concentration (2−3 vs 0.04%). The experimental data also provide information on the chemical nature and environment of the Ru complex that resides at or near the extreme liquid−vacuum interface.

The facile synthesis of a stable and isolable compound with a fluoroalkynyl group, M−C≡CF, is reported. Reaction of [Ru(C≡CH)(η5‐C5Me5)(dppe)] with an electrophilic fluorinating agent (NFSI) results in the formation of the fluorovinylidene complex [Ru(=C=CHF)(η5‐C5Me5)(dppe)][N(SO2Ph)2]. Subsequent deprotonation with LiN(SiMe3)2 affords the fluoroalkynyl complex [Ru(C≡CF)(η5‐C5Me5)(dppe)]. In marked contrast to the rare and highly reactive examples of fluoroalkynes that have been reported previously, this compound can be readily isolated and structurally characterized. This has allowed the structure and bonding in the CCF motif to be explored. Further electrophilic fluorination of this species yields the difluorovinylidene complex [Ru(C=CF2)(η5‐C5Me5)(dppe)][N(SO2Ph)2].