a ring $r$ is a strongly clean ring if every element in $r$ is the sum of an idempotent and a unit that commutate. we construct some classes of strongly clean rings which have stable range one. it is shown that such cleanness of $2 imes 2$ matrices over commutative local rings is completely determined in terms of solvability of quadratic equations.

A ring $R$ is a strongly clean ring if every element in $R$ is the sum of an idempotent and a unit that commutate. We construct some classes of strongly clean rings which have stable range one. It is shown that such cleanness of $2 imes 2$ matrices over commutative local rings is completely determined in terms of solvability of quadratic equations.

We report on the block copolymerization of two structurally different norbornene monomers (±)-endo,exo-bicyclo[2.2.1]-hept-5-ene-2,3-dicarboxylic acid dimethylester (7), and (±)-endo,exo-bicyclo[2.2.1]-hept-5-ene-2,3-dicarboxylic acid bis(1-oxyl-2,2,6,6-tetramethyl-piperidin-4-yl) ester (9) using ruthenium based Grubbs' type initiators [(PCy₃)₂Cl₂Ru(benzylidene)] G1 (PCy₃ = tricyclohexylphosphi...

The hyperpolarization (HP) method signal amplification by reversible exchange (SABRE) uses para-hydrogen to sensitize substrate detection by NMR. The catalyst systems [Ir(H)2(IMes)(MeCN)2(R)]BF4 and [Ir(H)2(IMes)(py)2(R)]BF4 [py = pyridine; R = PCy3 or PPh3; IMes = 1,3-bis(2,4,6-trimethylphenyl)imidazol-2-ylidene], which contain both an electron-donating N-heterocyclic carbene and a phosphine, ...

The reaction of [Ir(IMes)(COD)Cl], [IMes 1⁄4 1,3-bis(2,4,6-trimethylphenyl)imidazol-2-ylidene, COD 1⁄4 1,5cyclooctadiene] with pyridazine (pdz) and phthalazine (phth) results in the formation of [Ir(COD)(IMes)(pdz)]Cl and [Ir(COD)(IMes)(phth)]Cl. These two complexes are shown by nuclear magnetic resonance (NMR) studies to undergo a haptotropic shift which interchanges pairs of protons within th...

Complex [(IMes)(2)Pt(H)(ClBC(5)H(4)SiMe(3))] (IMes = 1,3-di(2,4,6-trimethylphenyl)imidazolin-2-ylidene) reacts with Lewis bases (L = pyridine, trimethylphosphine, acetonitrile, tert-butylisocyanide) to generate the kinetically favoured ion pairs [(IMes)(2)Pt(H)(L)][ClBC(5)H(4)SiMe(3)]. Over time, the formation of the thermodynamically favoured borabenzene-L adducts is observed with L = pyridine...

The development of a model system to study ruthenium-olefin complexes relevant to the mechanism of olefin metathesis has been reported recently. Upon addition of the ligand precursor 1,2-divinylbenzene to [RuCl(2)(Py)(2)(H(2)IMes)(==CHPh)] (H(2)IMes=1,3-dimesityl-4,5-dihydroimidazol-2-ylidene), two ruthenium-olefin adducts are formed. Based on (1)H NMR spectroscopy experiments and X-ray crystal...

An eta2-peroxopalladium(II) complex, derived from dioxygen addition to Pd(IMes)2 (IMes = bis-1,3-di(2,4,6-trimethylphenyl)imidazoline-2-ylidene), has been isolated and characterized. Subsequent addition of HOAc to (IMes)2Pd(O2) yields the first example of a hydroperoxopalladium species derived from molecular oxygen. The characterization and reactivity studies of these complexes provide the most...

Abstract Mirfentanil, a fentanyl derivative that is μ ‐opioid partial agonist, hyperpolarised via Signal Amplification By Reversible Exchange (SABRE), para ‐hydrogen‐based technique. [Ir(IMes)(COD)Cl] (IMes=1,3‐ bis (2,4,6‐trimethylphenyl)imidazole‐2‐ylidene, COD=cyclooctadiene) was employed as the polarisation transfer catalyst. Following at 6.5 mT, pyrazine‐protons were enhanced by 78‐fold (p...

The Ru-hydride precursors (Im(OMe)2)(PPh3)2RuHCl () and (Me2Im(OMe)2)(PPh3)2RuHCl () reacted with ethyl-vinyl-sulfide to give ((MeOCH2CH2)C3H2N2(CH2CH(OMe))RuCl(PPh3)2 () and ((MeOCH2CH2)C3Me2N2(CH2CH(OMe))RuCl(PPh3)2 (), respectively. Dissolution of () in C6D6 prompts formation of ((MeOCH2CH2)C5H6N2(CHCH)RuCl(PPh3)2 (). The analogous reactions of the bis-carbene Ru-hydride precursors (Im(OMe)2...