Electronic effects in some ruthenium(II)–carbonyl and –tertiary phosphine or –tertiary arsine complexes

Abstract

New complexes of the types [RuX,(CO)L,], [RuXY(CO)L,]. [RuX,(CO),L,], and [Ru,X,L6] [anion] (X = C1. Br, or I ; Y = H. CI. Br, I. NO, , acetate, propionate, or benzoate ; L = PR, or AsR,) are described. The hydrido-complexes [RuHX(CO)(PR,),]. configuration (111). react with nitric acid or carboxylic acids to give complexes of the type [RuXY(CO)(PR,),](Y = NO, or carboxylate) but with halogen acids (HY) mixtures are formed. An arsine hydrido-complex [RuHCI(CO) (AsMe,Ph),] is described. The ruthenium-chlorine stretching frequencies for these complexes are recorded and discussed. Tertiary phosphines cause much weakening of a rutheniumchlorine bond in trans-position, and carbon monoxide is a poorly trans-bond weakening ligand but causes more weakening than chlorine as trans-ligand. These bond-weakening effects are discussed. There is good correlation between a low ruthenium-chlorine stretching frequency and a high lability of the chlorine towards nucleophilic displacement; inert chlorines show high ruthenium-chlorine stretching frequencies. The stepwise formation of [RuICI(CO)(PMe,Ph),]and [Rul,(CO)(PMe,Ph),] from [RuCI,(CO)(PMe,Ph),], configuration (11) by nucleophilic displacement of chloride by iodide, has been followed by an n.m.r. method. N.m.r. data and values for vczo are given.A LARGE range of stable carbonyl, dicarbonyl, and hydridocarbonyl complexes of ruthenium(I1) containing neutral ligands (L) such as tertiary phosphines, and halogeno-ligands (X) can be prepared.l* We first describe some new complexes of these types and then show how they and those described previously illustrate trans-bond weakening and trans-bond labilising effects in ruthenium(I1) complexes. The carbonyl complexes described have the configurations (1)-(VI) and the same numbering system as before will be used.The salts of type [Ru2X2L6] [anion] were prepared as described previously; 2p6 several of the complexes are new. Treatment of ruthenium trichloride with PPr2Ph in ethyl methyl ketone gave the ruthenium(1n) complex [RuC13(PPr2Ph),]. Complexes of the type me+ [RuCl,(MEt,Ph),] (M = P or As) have been described previously.MonocarbonyZ ComfiZexes.-These were prepared by established methods, sometimes slightly modified, e.g., when the salt [RU&13(PPr2Ph)6]C1 was treated with

Synthesis and reactivity of ruthenium(II) complexes containing hemilabile phosphine–thiophene ligands

“…Since CO is a strong π-acceptor, any trans ligand competing for electron density from the metal center will weaken the M-CO bond and this trans influence decreases in the order CO > P > Cl. 44 Thus, complexes containing a chloro trans to a carbonyl are thermodynamically more stable than isomers with either a phosphine or a CO trans to a carbonyl, as reported in the literature. 43,45,46 When 8 reacts with CO at room temperature, only 10 forms while the reaction of 9 with CO yields only 11.…”

A kinetic study of the hydrogenation of hexene-1 catalyzed by a ferrocenyl-phosphine derivative of ruthenium(II)

“…Finally, the infrared spectrum shows a single band at 310 cm-' that is characteristic of v(Ru-C1) with mutually trrzns chlorides (22,25 For personal use only.…”

Synthesis and Structure of New (Polyphosphane)ruthenium Complexes with the Hemilabile Ligand 2‐(Diphenylphosphanyl)‐1‐methyl‐1H‐imidazole − An Unexpected Rearrangement of [RuCl2(PN)(PPh3)2]

“…, which is characteristic of ν(RuϪCl) with mutual trans-chloride ions. [14,15] The FAB ϩ mass spectrum is in complete agreement with the expected fragmentation pattern and contains a peak corresponding to the fragment [RuCl(PPh 3 ) 2 ϩ (m/z ϭ 403). On the basis of these data, the structure of 1, which must be present as a mixture of enantiomers, is believed to be that shown in Scheme 2.…”