Preparation and characterization of the dimetallo ketone complexes Ir2(.mu.-S-tert-Bu)2(.mu.-CO)L2(CO)2I2: crystal and molecular structure of the [iridium] complex where L = trimethylphosphine (original) (raw)
Inorganic Chemistry, 2013
This work details the synthesis and structural identification of a series of complexes of the (η 5 -C 5 Me 5 )Ir(III) unit coordinated to cyclometalated bis(aryl)phosphine ligands, PR′(Ar) 2 , for R′ = Me and Ar = 2,4,6-Me 3 C 6 H 2 , 1b; 2,6-Me 2 -4-OMe-C 6 H 2 , 1c; 2,6-Me 2 -4-F-C 6 H 2 , 1d; R′ = Et, Ar = 2,6-Me 2 C 6 H 3 , 1e. Both chloride-and hydride-containing compounds, 2b−2e and 3b−3e, respectively, are described. Reactions of chlorides 2 with NaBAr F (BAr F = B(3,5-C 6 H 3 (CF 3 ) 2 ) 4 ) in the presence of CO form cationic carbonyl complexes, 4 + , with ν(CO) values in the narrow interval 2030−2040 cm −1 , indicating similar π-basicity of the Ir(III) center of these complexes. In the absence of CO, NaBAr F forces κ 4 -P,C,C′,C″ coordination of the metalated arm (studied for the selected complexes 5b, 5d, and 5e), a binding mode so far encountered only when the phosphine contains two benzylic groups. A base-catalyzed intramolecular, dehydrogenative, C−C coupling reaction converts the κ 4 species 5d and 5e into the corresponding hydrido phosphepine complexes 6d and 6e. Using CD 3 OD as the source of deuterium, the chlorides 2 undergo deuteration of their 11 benzylic positions whereas hydrides 3 experience only D incorporation into the Ir−H and Ir−CH 2 sites. Mechanistic schemes that explain this diversity have come to light thanks to experimental and theoretical DFT studies that are also reported.
Structural …, 1996
The energetics of the oxidative additive of 12 to [Ir(/.t-L)(CO)2]2 [L = t-buthylthiolate (S'Bu), 3,5-dimethylpyrazolate (3,5-Me2pz), and 7-azaindolate (7-aza)] complexes was investigated by using the results of reaction-solution calorimetric measurements, X-ray structure determinations, and extended HiJckel (EH) molecular orbital calculations. The addition of I mol of iodine to 1 mol of [Ir(/~-L)(CO)2]2, in toluene, leads to [Ir(/z-L)(l)(CO),.]2, with the formation of two Ir--I bonds and one Ir--lr bond. The following enthalpies of reaction were obtained for this process: -125.8 __ 4.9 kJ mol -I (L = S'Bu), -152.0 +_ 3.8 kJ mol -I (L = 3,5-Me2pz), and -205.9 4-9.9 kJ mol -~ (L = 7-aza). These results are consistent with a possible decrease of the strain associated with the formation of three-, four-, and five-membered rings, respectively, in the corresponding products, as suggested by the results of EH calculations. The calculations also indicate a slightly stronger Ir--Ir bond for L = 3,5-Me,_pz than for L = S'Bu despite the fact that the Ir--Ir bond lengths are identical for both complexes. The reaction of l mol of [Ir(p,-S'Bu)(CO)2] 2 with 2 mol of iodine to yield [Ir(tt-S'Bu)(I)2(CO)2]2 was also studied. In this process four Ir--I bonds are formed, and from the corresponding enthalpy of reaction (-186.4 _ 2.7 kJ tool -~) a solution phase Ir--I mean bond dissociation enthalpy in [Ir(p,-S'Bu)(I)2(CO)2]2, DH~ln(Ir--I) = 122.2 _ 0.7 kJ mol -t, was derived. This value is lower than most D--H, in values reported for octahedral mononuclear Ir m complexes. New large-scale syntheses of the [Ir(/z-L)(CO)2]2 complexes, with yields up to 90%, using [Ir(acac)(CO)2] as starting material, are also reported. The X-ray structures of [Ir(#-L)(I)(CO)2]2 (L = S'Bu and 3,5-MeEpz) complexes have been determined. For L = S'Bu the crystals are monoclinic, space group P2dc, a = 10.741(2) ,~, b = 11.282(3) ,4,, c = 1.8.308(3) ,~,,/3 = 96.71(1) ~ and Z = 4. Crystals of the/.t-3,5-MeEpz derivative are monoclinic, space group P2t/n, a = 14.002(3) A., b = 10.686(1) ,~, c = 15.627(3) tk, t3 = 112.406(8) ~ and Z = 4.
Organometallics, 2005
The cis-[RuCl 2 (PPh 3 ) 2 (N-N)] (N-N ) bipy (1), Me-bipy (2), phen (3), and bathophen (4)) complexes were used to synthesize five new electron-rich phosphine-containing complexes cis-[RuCl 2 (dcype)(N-N)] (N-N ) bipy (1a), Me-bipy (2a), phen (3a), and bathophen (4a)) and cis-[RuCl 2 (PEt 3 ) 2 (bipy)] (1c) by phosphine exchange. These complexes were obtained and characterized by NMR ( 31 P{ 1 H}, 1 H), cyclic voltammetry, and elemental analysis. Electrochemical studies of these complexes reveal a single reduction process (Ru III /Ru II ). These complexes are more easily oxidized than their analogues cis-[RuCl 2 (dppb) ]. The reactivity of complexes cis-[RuCl 2 (dcype)(N-N)] with carbon monoxide was tested, and dissociation of one chloride was observed, leading to the formation of four new cationic species with general formula [RuCl(CO)(dcype)(N-N)](PF 6 ) (bipy (1b), Me-bipy (2b), phen (3b), and bathophen (4b)). The complexes described here and elsewhere with general formulas cis-[RuCl 2 (P-P)(N-N)], [RuCl(CO)(dcype)(N-N)](PF 6 ), and cis-[RuCl 2 (P) 2 (N-N)] were used as precatalysts in the transfer hydrogenation of functionalized aryl-ketones, and most of them were active. X-ray structures of cis-[RuCl 2 (PEt 3 ) 2 (bipy)] (1c) and [RuCl(CO)(dcype)(bipy)]-(PF 6 ) (1b) will be presented.
Syntheses and crystal structures of the first iridium complexes with m- and p-terphenyl (tp). {Ir2(p-tp)(cod)22·2CH2Cl2}3 and Ir(m-tp)(η5-C5Me5)2
Inorganica Chimica Acta, 2004
Novel two iridium terphenyl complexes were prepared and their structures were characterized crystallographically. The reaction of [Ir(cod) 2 ]BF 4 with p-terphenyl (p-tp) in CH 2 Cl 2 was carried out to afford dinuclear Ir(I) complex {[Ir 2 (p-tp)(cod) 2 ](BF 4 ) 2 Á 2CH 2 Cl 2 } 3 (cod ¼ 1,5-cyclooctadiene) (1 Á 2CH 2 Cl 2 ), whereas the reaction of the intermediate [Ir(g 5 -C 5 Me 5 )(Me 2 CO) 3 ] 3þ in Me 2 CO with m-terphenyl (m-tp) was done to provide mononuclear Ir(III) complex [Ir(m-tp)(g 5 -C 5 Me 5 )](BF 4 ) 2 (2). In complex 1 Á 2CH 2 Cl 2 , two Ir atoms are g 6 -coordinated to both sides of terminal benzene rings from the upper and lower sides in the p-tp ligand, while one Ir atom is g 6 -coordinated to one side of the terminal benzene ring in the m-tp ligand in complex 2. Each crystal structure describes the first coordination mode found in metal complexes with the m-and p-tp ligands.
Butadienesulfonyl iridium complexes with phosphine and carbonyl ligands
Journal of Organometallic Chemistry, 2019
The metathesis reaction of IrCl(CO)(PPh 3) 2 (4) and Vaska-type derivatives IrCl(CO)(PR 3) 2 (PR 3 ¼ MePh 2 , 5; Me 2 Ph, 6; Me 3 , 7) with 1e2 equivalents of the potassium butadienesulfinate salts K(SO 2 CHCRCHCH 2) (R ¼ H, 2; Me, 3) led to the formation of mixtures of chiral diastereomers "a" and "b" of general formula Ir(1e2,5-h-CH 2 CHCRCHSO 2)(CO)(L) 2
Chemistry of (.eta.5-C5Me5)Ir(CO)2. 1. Metal-metal bond formation employing a basic metal center
Organometallics, 1986
The binuclear complex (q5-C5Me5)(OC) [ (i-PrO),P]IrRhCl(CO) [P(O-i-Pr)3] (1) has been prepared by the reaction of (q5-C5Me5)Ir(C0)2 with ((p-Cl)Rh[P(O-i-Pr),1,1, at 90 'C in toluene. The structure of 1 has been determined by single-crystal X-ray diffraction. Compound 1 crystallizes in the monoclinic space grou P21/n-C2h5 (no. 14) with four molecules in a unit cell of dimensions a = 11.463 (4) A, b = 15.888 (6) (c = 22.417 (6) A, and 0 = 99.01 (2) O. Least-squares refinement led to a value for the conventional R index (on F) of 0.045 for 5093 independent reflections having 2eMoKn < 55.0' and I > 3 b(I). The crystallographic investigation confirmed the formulation of 1 as a heterobimetallic complex possessing an unsupported Ir-Rh bond of 2.797 (1) A. Spectroscopic investigations indicate the metal-metal bond remains intact in solution, but it is susceptible to cleavage by ligands, L, affording (q5-C5Me5)Ir(C0)[P(O-i-Pr),] and trans-ClRh-(L)(L')[P(O-i-Pr),] (where L = P-i-Pr3, L' = CO and L = t-BuNC, L' = t-BuNC). Reaction of (q5-C5Me5)Ir(C0)2 with ((p-C1)Rh[P(OR)3]2)2 (R = Me, Et, Ph) did not yield binuclear analogues of 1 but instead gave (q5-C5Me5)Ir(CO)[P(OR),] and ((p-C1)Rh(CO)[P(OR),])2.
Synthesis and structure of the first monomeric iridium–siloxide complexes
Inorganica Chimica Acta, 2002
The first monomeric iridium Á/siloxide complexes [Ir(cod)(PCy 3 )(OSiMe 3 )] (1), [Ir(cod)(PCy 3 )(OSiMe 2 CHÄ/CH 2 )] (2) and [Ir(CO)(PPh 3 ) 2 (OSiMe 3 )] (3), whose structures have been successfully determined by the X-ray method, have been synthesised and characterised by 1 H, 13 C, 31 P and 29 Si NMR spectroscopy. In all three complexes the coordination of iridium is square planar. # .pl (B. Marciniec).