Novel Cu(II)-M(II)-Cu(II) (M = Cu or Ni) trinuclear and [NaCu] hexanuclear complexes assembled by bi-compartmental ligands: syntheses, structures, magnetic and catalytic studies.
In the present work, two compartmental ligands H2L(1) and H2L(2) were in situ generated during the syntheses of new trinuclear complexes, [Cu2Ni(L(1))(2,2'-bpy)2(NO3)2][ClO4]2 (), [Cu3(L(2))(NO3)2][ClO4]2 (), and [Cu3(L(2))(NCS)2(NO3)](+) that co-crystallize in with a [Cu6(L(2))2Na2(NO3)6(NCS)4] unit to give the final molecular formula [Cu6(L(2))2Na2(NO3)6(NCS)4][Cu3(L(2))(NCS)2(NO3)]2(NO3)2·5H2O (). The magnetic property studies of revealed weak Cu(II)-Cu(II) ferromagnetic interactions in compound (JCu-Cu/kB = +1.4(1) K) and (JCu-Cu/kB = +1.6) while in intranuclear Cu(II)-Ni(II)-Cu(II) compound , the magnetic coupling between two Cu(II) ions is switched off by the diamagnetic square planar Ni(II) bridge. The catalytic epoxidation of two olefins, namely styrene and cyclooctene, by tert-BuOOH (TBHP) was also explored in the presence of a catalytic amount of , or in MeCN. For styrene oxidation, exhibited ∼57% styrene epoxide selectively (conversion ∼37%) with a TON of about 925 along with benzaldehyde (∼43%), whereas exhibited conversion up to ∼63% (TON ∼ 1575) with a good selectivity towards epoxide (∼71%). For compound , this conversion is more important (TON ∼ 8108) probably due to the presence of more active sites involved in the epoxidation. The concerted path was found to be operative for styrene oxidation while a radical path was suggested for the oxidation of cyclooctene.
Department of Chemistry Jadavpur University, Kolkata 700 032, India. mali@chemistry.jdvu.ac.in.
Surajit
S
Biswas
Arpan
A
Dutta
Malay
M
Dolai
Indrani
I
Bhowmick
Mathieu
M
Rouzières
Rodolphe
R
Clérac
Anangamohan
A
Panja
Mahammad
M
Ali
D002384:Catalysis; D060326:Chemistry Techniques, Synthetic; D003300:Copper / Q000737:chemistry*; D034242:Cyclooctanes / Q000737:chemistry; D004852:Epoxy Compounds / Q000737:chemistry; D008024:Ligands; D060328:Magnetic Phenomena; D008958:Models, Molecular; D008968:Molecular Conformation; D009942:Organometallic Compounds / Q000138:chemical synthesis* / Q000737:chemistry*; D016877:Oxidants / Q000737:chemistry; D020058:Styrene / Q000737:chemistry; D020122:tert-Butylhydroperoxide / Q000737:chemistry
D034242:Cyclooctanes; D004852:Epoxy Compounds; D008024:Ligands; D009942:Organometallic Compounds; D016877:Oxidants; D020058:Styrene; D003300:Copper; D020122:tert-Butylhydroperoxide