Synthesis and electronic structure of the first cyaphide-alkynyl complexes

Abstract

The novel complexes trans-[Ru(dppe)2(C≡CR)(C≡P)] (R = CO2Me, C6H4OMe), the first to incorporate cyaphide as part of a conjugated system, are obtained in facile manner. The electronic structure of these compounds is probed by X-ray, DFT and UV/Vis studies.

Through-conjugation of two phosphaalkyne (‘CP’) moieties mediated by a bimetallic scaffold

“…(i) reduction in frequency of the CuP stretch (Δν CuP ∼ −12 cm −1 ); (ii) loss of NMR resonances for silyl and − OTf moieties; (iii) increase in frequency (Δδ P 48) for the phosphaalkynic P-centres, with reduced magnitude of the P CP -P dppe coupling ( precluding its resolution); (iv) increased frequency (Δδ c 92) for the cyaphidic carbon resonance, consistent with formation of an organometallic linkage (cf M-CO, M-CN). These data compare well with those we have noted previously 16 and those for Grutzmacher's seminal complex [RuH (dppe) 2 (CuP)]; 20a they also concur with data calculated for 3 using the PBE functional ( Table 1).…”

“…bis-alkynyl complexes) was unexplored prior to our recent report of the unprecedented cyaphide-alkynyl complexes trans-[Ru(dppe) 2 (CuCR)(CuP)] (R = CO 2 Me, p-An). 16 Herein, we extend this conceptual framework to consider, for the first time, extended conjugation between multiple 'CuP' moieties, mediated by a bimetallic, redoxactive, core; we also elucidate the electronic and redox nature of these complexes.…”

“…19 The coordinated phosphaalkyne moieties are similarly consistent with related analogues. [14][15][16]20 Conversion of the η 1 -PuCSiMe 3 moieties to terminal cyaphide ligands ('-CuP') proceeds upon treating 2 2+ with 2 equiv. KO t Bu, 21 affording 3 in moderate yield (Scheme 1).…”

Organophosphorus Compounds in Organic Electronics

“…Further studies are ongoing to explore if further coordination of the significantly stabilized P lone pair (HOMO−7 and HOMO−8, ca. 1.6 eV below the HOMO) is possible …”

η1:η2-P-Pyrazolylphosphaalkene Complexes of Ruthenium(0)

“…First described in 1985 [24], such systems remain relatively rare, though-with the exception of type E-all possible motifs have been realized, with P-metalla-(type A) and C-metalla-(type B) systems the most heavily studied. Recently, as part of an extended program investigating transition metal compounds featuring low-coordinate phosphacarbons with potential for conjugation [25][26][27][28], we have prepared and studied a range of ruthenaphosphaalkenyl complexes of the type [Ru{P=CH(SiMe2R)}Cl(CO)(PPh3)2] (R = Me 1a, Ph 1b, Tol 1c) [29,30]. These are prepared by hydroruthenation of phosphaalkynes R3SiC≡P, following from methodology developed initially by Hill and Jones for t BuC≡P and related systems [31][32][33], and superficially related to Nixon's independent reduction of [(Ph3P)2Pt(η 2 -P≡C t Bu)] with Schwartz's reagent [34].…”