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New chiral P,N-hybrid aryl phosphites have been obtained by one-step phosphorylation of amino and imino alcohols. Complexation of the new ligands with [Rh(CO) 2 Cl] 2 , [Pd(COD)Cl 2 ] and [Pd(allyl)Cl] 2 was found to give chelate complexes [Rh(CO)Cl(η 2 -P ʝ N)], [PdCl 2 (η 2 -P ʝ N)] and [Pd-(allyl)(η 2 -P ʝ N)] + Cl − , respectively. With these new P,N-ligands, up to 82% ee enantioselectivity was achieved in the [a] The new P,N-bidentate aryl phosphites were synthesized by one-step phosphorylation of the corresponding amino and imino alcohols with bis(2,6-dimethylphenyl) chlorophosphite.They divide into two groups: ligands 3aϪ3f, possessing sp 3 -hybridized nitrogen atoms, and ligands 3gϪ3m, which have sp 2 -hybridized nitrogen atoms. All the compounds 3aϪm are soluble in conventional organic solvents and stable under dry conditions for several months. On treatment with [Rh(CO) 2 Cl] 2 , their neutral carbonyl(chloro)Rh I complexes were obtained.The ν(CO) and 1 J P,Rh parameters in their IR and 31 P NMR spectra act as sensitive indicators, which characterise the mode of complexation of the P,N-ligands and allow the π-acceptor ability of the phosphorus centre and the degree of electronic non-symmetry of the ligands to be estimated. [13Ϫ15] In general, ligands 3aϪ3m give chelate complexes. Thus, the

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Extensive experimental and theoretical investigations are reported on the nature of resonance-assisted hydrogen bonding phenomenon (RAHB) and its influenceo n photophysical properties of the newly designed dyes differing in donor-acceptor properties, namely ethyl N-salicylideneglycinate (1), ethyl N-(5-methoxysalicylidene)glycinate (2), ethyl N-(5-bromosalicylidene)glycinate (3)a nd ethyl N-(5-nitrosalicylidene)glycinate(4). All compounds are thermochromic in the solid state and they contain at ypical intramolecular OÀH•••N hydrogen bond formed between the hydroxyl hydrogen atom and the imine nitrogen atom, yielding the enol form in the solid state. It is unveiled, that the magnitude of RAHB effect fine tunes the strength of the OÀH•••N bondinga nd accordingly the relativep opulations of the enol, cis-keto and trans-keto formsl eading to variation of the photophysical properties of 1-4.I ti sd etermined, that the electron-withdrawing NO 2 in 4 amplifies the mostR AHB effectc ausing the breaking of the OÀH•••N hydrogenb ond and accordingly formation of the dominant cis-keto isomer in both the solid state and EtOH. To this end, the UV/Vis spectra of 1-3 in EtOH revealed the exclusive presence of the enol form, while the prevalent contribution of the cisketo form was found for 4.F urthermore, only compound 4 is emissive in the solids tate in ambient condition due to dual emissiona rising from the cis-keto* and trans-keto* forms,w hile 2 was found to be highly emissive in EtOH. It is revealed qualitativelya nd quantitatively,b ased on the ETS-NOCV charge and energy decomposition scheme and the EDDB population-based method, that RAHB is strongly a non-local phenomenon based on electrons pumping or suckingt hrough both the p-a nd s-channels, which accordingly exerts chemicalb ondingc hanges at both the phenyl ring and predominantly ad istant OÀH•••N area.