Synthesis and characterization of polypyridineruthenium(II) complexes containing a linear ambidentate ligand, NCO− or NCS−, and reaction of isocyanato complexes under acidic conditions

Comparative reactivity studies of dppf-containing CpRuII and (C6Me6)RuII complexes towards different donor ligands (dppf=1,1′-bis(diphenylphosphino)ferrocene)

“…In comparison, it is noted that the m CBN stretching frequencies in [CpRu( [27] and [Ru(NCS)(NO)-(bpy)(py) 2 ](PF 6 ) 2 [28] were found at 2030, 2120 and 2097 cm À1 , respectively, with m C-S at 808, 780 cm À1 and in the m PF6 region, respectively. The m CBN stretching vibration of coordinated acetonitrile is seen at 2259 cm À1 in 6, 2363 cm À1 in 7 and 2359 cm À1 in 14.…”

Ruthenium(ii) and ruthenium(iv) complexes containing hemilabile heterodifunctional iminophosphorane-phosphine ligands Ph2PCH2P(NR)Ph2

“…This can be assessed spectroscopically by: (i) a strong downfield shift of the 31 P-{ 1 H} NMR signals with doublets ( 2 J(PP) = 15.5-22.0) in the ranges δ P 48.3-50.0 (Ph 2 P) and 54.5-55.3 (Ph 2 P᎐ ᎐ N), as well as a slight deshielding (ca. 18 We decided in favor of N-bonding on the basis of the following considerations: (i) Both N-and O-bonded models were refined to convergence, and the former gave significantly lower residuals (R = 0.0637 and R w = 0.0708 as against R = 0.0652 and R w = 0.0723). (ii) The chemical inequivalence of the methylenic PCH 2 P protons which appear as one or two unresolved multiplets at 3.20-4.04 ppm.…”

“…It is worth mentioning that in transition-metal cyanato compounds a decision between Nand O-bonding from X-ray structural analysis is not so straightforward because of the very similar sizes and scattering factors for N and O. 18 We decided in favor of N-bonding on the basis of the following considerations: (i) Both N-and O-bonded models were refined to convergence, and the former gave significantly lower residuals (R = 0.0637 and R w = 0.0708 as against R = 0.0652 and R w = 0.0723). (ii) The virtual linearity of the Ru-N-C-O chains is more consistent with the N-bonded model.…”

Cationic versus Neutral RuIIN‐Heterocyclic Carbene Complexes as Latent Precatalysts for the UV‐Induced Ring‐Opening Metathesis Polymerization

“…To distinguish between isocyanate and cyanate coordination further we recorded the IR spectra of 5 and the values for the ũ CN band at 2247 cm À1 were in accordance with those of other Ru À isocyanate complexes. [16][17] ROMP with precatalysts 1-5/UV activation: Upon mixing of the precatalysts 1-5 with monomers 6-9 and 11 (Scheme 1) no reaction was observed for precatalysts 1 and 2 either at room temperature or by heating the mixture for 24 h to 50 8C. These two cationic complexes have trifluoromethansulfonate ligands, which are known to be capable of binding to the metal centers through m 2 -coordination.…”