Polymer-anchored mononuclear and binuclear Cu^II Schiff-base complexes: Impact of heterogenization on liquid phase catalytic oxidation of a series of alkenes

DATA S1 Supplementary Information

informationFT-IR, electronic and EPR spectra, 1H NMR, 13C NMR, AAS, AFM, SEM, EDX, LC-MS and ESI-MS data of the ligands, supportedand neat copper complexes, recyclability, and catalytic data for the oxidation of alkenes by the reported neatand supported catalysts.

FIGURE S1 FT-IR spectra of ligand [Hsal-sch] (I), [Hsal-tch] (II), [H₂bissal-sch] (III) and [H₂bissal-tch] (IV)

FIGURE S2 FT-IR spectra of complex [Cu (sal-sch)Cl] (1), [Cu (sal-tch)Cl] (2), [CH₂{Cu (sal-sch)Cl}₂] (3) and [CH₂{Cu (sal-tch)Cl}₂] (4)

FIGURE S3 FT-IR spectrum of chloromethylated polystyrene swelled in methanol

FIGURE S4 IR spectra of complex PS-[Cu (sal-sch)Cl] (5), PS-[Cu (sal-tch)Cl] (6), PS-[CH₂{Cu (sal-sch)Cl}₂] (7) and PS-[CH₂{Cu (sal-tch)Cl}₂] (8)

FIGURE S5 Electronic spectra of (a) ligands (I)–(IV) and (b) copper complexes (1)–(4) recorded in methanol

FIGURE S6 Electronic spectra of fresh and recycled polymer-anchored complexes: (a) PS-[Cu (sal-sch)Cl] (5); (b) PS-[Cu (sal-tch)Cl] (6); (c) PS-[CH₂{Cu (sal-sch)Cl}₂] (7); and (d) PS-[CH₂{Cu (sal-tch)Cl}₂] (8) recorded in Nujol

FIGURE S7 Plot comparing the d-d transitions of copper complexes (1)–(4) recorded in DMF

FIGURE S8 Gas phase optimized molecular structure of: (a) 1; (b) 2; (c) 3 and (d) 4 calculated using DFT/B3LYP/LANL2DZ ∪ 6–311 + G(d, p) method

FIGURE S9 Molecular orbital diagram for the complex [Cu (sal-sch)Cl] (1)

FIGURE S10 Molecular orbital diagram for the complex [Cu (sal-tch)Cl] (2)

FIGURE S11 Molecular orbital diagram for the complex [CH₂{Cu (sal-sch)Cl}₂] (3)

FIGURE S12 Molecular orbital diagram for the complex [CH₂{Cu (sal-tch)Cl}₂] (4)

FIGURE S13 HOMO orbital composition of complexes 1–4

FIGURE S14 LUMO orbital composition of complexes 1–4

FIGURE S15 DTA-TGA plots of polymer-anchored Cu^II complexes 5–8

FIGURE S16 DTG plots of metal complex grafted polymers 5–8

FIGURE S17 AFM pictures (left) and corresponding 3D-surface maps (*) of: (a) PS-Cl; (b) PS- [Cu (sal-sch)Cl] (5); (c) PS-[Cu (sal-tch)Cl] (6); (d) PS-[CH₂{Cu (sal-sch)Cl}₂] (7); and (e) PS-[CH₂{Cu (sal-tch)Cl}₂] (8)

FIGURE S18 % conversion of the oxidation of cyclohexene, cis-cyclooctene, styrene, 1-methyl cyclohexene and 1-hexene under optimized reaction conditions in the presence of fresh and recycled catalysts

FIGURE S19 FT-IR spectra of recycled polymer-anchored complex PS-[Cu (sal-sch)Cl] (5^Ŗ), PS-[Cu (sal-tch)Cl] (6^Ŗ), PS-[CH₂{Cu (sal-sch)Cl}₂] (7^Ŗ) and PS-[CH₂{Cu (sal-tch)Cl}₂] (8^Ŗ)

FIGURE S20 SEM images of used: (a) PS-[Cu (sal-sch)Cl] (5^Ŗ); (b) PS-[Cu (sal-tch)Cl] (6^Ŗ); (c) PS-[CH₂{Cu (sal-sch)Cl}₂] (7^Ŗ); and (d) PS-[CH₂{Cu (sal-tch)Cl}₂] (8^Ŗ)

FIGURE S21 EDX plots of used: (a) PS-[Cu (sal-sch)Cl] (5^Ŗ); (b) PS-[Cu (sal-tch)Cl] (6^Ŗ); (c) PS-[CH₂{Cu (sal-sch)Cl}₂] (7^Ŗ); and (d) PS-[CH₂{Cu (sal-tch)Cl}₂] (8^Ŗ)

FIGURE S22 LC–MS; (a) chromatogram; and (b) MS spectrum of the H₂O₂ mixed methanolic solution of 1

FIGURE S23 Change in EPR spectra observed during the slow addition of dilute H₂O₂ into the methanolic solution of (1)

FIGURE S24 ESI-mass spectrum of [Cu (sal-sch)Cl] (1)

FIGURE S25 ESI-mass spectrum of [Cu (sal-tch)Cl] (2)

FIGURE S26 ESI-mass spectrum of [CH₂{Cu (sal-sch)Cl}₂] (3)

FIGURE S27 ESI-mass spectrum of [CH₂{Cu (sal-tch)Cl}₂] (4)

TABLE S1 ¹H-NMR spectral data (δ in ppm) of ligands (I)–(IV) recorded in DMSO-d₆

TABLE S2 ¹³C-NMR spectral data of ligands (I)–(IV) recorded in DMSO-d₆

TABLE S3 Spin Hamiltonian parameters of neat Cu^II complexes 1–4 in DMSO solution and polymer-anchored Cu^II complexes 5–8 in solid state at room temperature

TABLE S4 Important experimental and theoretical bond distances (Å) along with bond angles (°) for complexes 1–4

TABLE S5 Average roughness and mean height of the supported complexes 5–8 and PS-Cl

TABLE S6 Selectivity of the oxidized products of styrene

TABLE S7 Product % selectivity, % conversion and TOF values of oxidation of 1-methyl cyclohexene with H₂O₂ under optimized reaction conditions

TABLE S8 Selectivity of the oxidized products of 1-hexene

TABLE S9 AAS data of one time used polymer-anchored copper (II) complexes 5–8