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1 H and 13 C NMR assignments with coordination‐induced shift calculations of carbon σ‐bonded ortho ‐metalated rhodium(III) and iridium(III) complexes
Author(s) -
Garces Fred O.,
Watts Richard J.
Publication year - 1993
Publication title -
magnetic resonance in chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.483
H-Index - 72
eISSN - 1097-458X
pISSN - 0749-1581
DOI - 10.1002/mrc.1260310603
Subject(s) - chemistry , iridium , heteronuclear molecule , rhodium , ligand (biochemistry) , homonuclear molecule , pyridine , deprotonation , crystallography , proton nmr , carbon 13 nmr , coordination sphere , nuclear magnetic resonance spectroscopy , stereochemistry , medicinal chemistry , crystal structure , molecule , ion , organic chemistry , catalysis , biochemistry , receptor
Complete 1 H and 13 C NMR assignments and coordination‐induced shift [CIS, δ (complex) – δ (free ligand) ] calculations for carbon σ‐bonded ortho ‐metalated rhodium(III) and iridium(III) complexes are described. NMR parameters are used as probes of van der Waals interactions and ring current anisotropy in the ligand's environmental framework and to monitor σ‐donation and π‐back‐bonding within the ligand in this family of ortho ‐metalated complexes. CIS measurements indicate large charge redistribution within the ligands as a result of ortho ‐metalation to the rhodium(III) or iridium(III) cationic metal centers. The pulse sequences, attached proton test (APT), 1 H 1 H homonuclear correlation spectroscopy (COSY), single‐frequency off‐resonance decoupling (SFORD) and 1 H 13 C heteronuclear correlation spectroscopy (HETCOR), were utilized to assign all proton and carbon resonances of [Rh(ppy) 2 Cl] 2 , [Ir(ppy) 2 Cl] 2 , [Ir(ptpy) 2 Cl] 2 , [Ir(mppy) 2 Cl] 2 , [Rh(ppy) 2 bpy] + , [Ir(ppy) 2 bpy] + , [Ir(ptpy) 2 bpy] + and [Ir(mppy) 2 bpy] + , where ppy is 2‐phenylpyridine, ptpy is 2‐( p ‐tolyl)pyridine, mppy is 3‐methyl‐2‐phenylpyridine and bpy is 2,2′‐bipyridine.