1H 13C NMR investigation of E/Z-isomerization around CN bond in the trans-alkene-Pt(II)imine complexes of some ketimines and aldimines

Highly active and thermostable camphyl α‐diimine–nickel(II) catalysts for ethylene polymerization: Effects of N‐aryl substituting groups on catalytic properties and branching structures of polyethylene

“…The increasing bulkiness of aryl groups ( L6 ) and the decreasing degree of substitution ( L2 ) tend to increase the rate of isomerization, which was also reported in the literature. [ 51,52 ] The α‐diimine–nickel(II) dibromide complexes ( L1 NiBr 2 – L6 NiBr 2 ) (Aryl = 2,6‐Me 2 C 6 H 3 [ L1 NiBr 2 , Ni1 ], 2,4‐Me 2 C 6 H 3 [ L2 NiBr 2 , Ni2 ], 2,4,6‐Me 3 C 6 H 2 [ L3 NiBr 2 , Ni3 ], 2,6‐Me 2 ‐4‐{(C 6 H 4 F) 2 CH}‐C 6 H 2 [ L4 NiBr 2 , Ni4 ], 2,4‐Me 2 ‐6‐{(C 6 H 4 F) 2 CH}‐C 6 H 2 [ L5 NiBr 2 , N5 ], and 2‐Me‐4,6‐{(C 6 H 4 F) 2 CH} 2 ‐C 6 H 2 [ L6 NiBr 2 , Ni6 ]) were synthesized in satisfactory yields (76% to 85%) by the metal coordination reaction of NiBr 2 ·DME with the corresponding ligands in dichloromethane at room temperature (Scheme 1). All nickel complexes have been characterized by elemental analysis and FT‐IR spectroscopy.…”

Transition Metal Complexes of Isonicotinoyl–hydrazone‐4‐diphenylaminobenzaldehyde: Synthesis, Characterization and Antimicrobial Studies

“…In the ligand spectrum νNH vibration from the imide group is located at 3053 cm -1 . The amide band I is situated at 1672 cm -1 and the band at 1590 cm -1 is assigned to the vibration corresponding to the azomethine group 16,17 . The amide II (δ NH) and amide III (γ NH) vibrations give bands in spectrum situated at 1554 cm -1 and 1331 cm -1 respectively.…”

Applications of nuclear shielding

“…Borate (b-BBO or b-BaB 2 O 4 ) was studied by static solid-state 135 Ba and 137 Ba NMR spectroscopies at 21.1 T and the measured quadrupolar coupling constants are 14.9 and 22.8 MHz for 135 Ba and 137 Ba, respectively. 77 The EFG tensor at Ba 2 þ was calculated by using both plane-wave pseudopotentials (CASTEP) and ab initio (Gaussian 03) methods.…”

“…It was found that the aldimine-and ketimine-platinum complexes undergo slow E/Z-isomerisation in solution as evidenced from NMR spectra. 135 Several groups exploring the 195 Pt NMR in solids, including metallic and magnetic materials, use different standards for chemical shift (Knight shift) determination. Commonly applied H 2 PtCl 6 and Na 2 PtCl 6 (IUPAC d scale) lead to considerable underestimation of the shifts since H 2 PtCl 6 has considerable own 195 Pt NMR shift due to its Van Vleck paramagnetism.…”