Author: Bera, Manindranath

Source: Journal of Chemical Research, Volume 2009, Number 8, August 2009 , pp. 527-532(6)

Publisher: Science Reviews 2000 Ltd

Abstract:

Two new dinuclear nickel(II) compounds of formula [Ni^II₂(μ-L¹)₂](ClO₄)₂·MeCN (1·MeCN) and [Ni^II₂(μ-L²)₂](ClO₄)₂(2) where HL¹ and HL² stand for 3-(2-(dimethylamino)ethylimino)butan-2-one oxime and 1-(2-(dimethylamino)ethyl-imino)-1-phenylpropan-2-one oxime respectively, have been synthesised. Single crystal X-ray analyses of the complexes reveal that the nickel(II) ions are in square-planar N₃O environments and form six-membered (NiNO)₂ metallacycles. Cyclic voltammetric measurements of 1·MeCN and 2 in MeCN solution show quasirreversible one-electron oxidations at E_1/2 = 0.566 V and 0.603 V (vs Fc⁺/Fc), respectively, attributed to Ni^IIINi^II/Ni^II₂ redox couples. Additional reversible Ni^III2/Ni^IIINi^II redox responses were observed at relatively higher potential near E_1/2 = 0.832 V and 0.850 V (vs Fc⁺/Fc), respectively, for 1·MeCN and 2.Complexes 1·MeCN and 2 display intense charge-transfer bands at ∼390 and ∼345 nm in the visible region. Chemical oxidation of complex 1·MeCN by sodium hexachloroiridate(IV) hexahydrate generates red Ni₂^III species with characteristic new bands at ∼520 and 427 nm in the visible region as well as the characteristic EPR signals at 77 K with g⊥ > g_II. Similar phenomena were observed for complex 2 upon chemical oxidation. The dinickel(II) complexes are catalytically active for epoxidation of olefins using iodosylbenzene as the terminal oxidant.

Keywords: DINICKEL(II) COMPLEX; OXIME LIGAND; X-RAY CRYSTAL STRUCTURE; NMR; OLEFIN EPOXIDATION

Document Type: Research article

DOI: http://dx.doi.org/10.3184/030823409X12491271131153

Publication date: 2009-08-01

More about this publication?

• The Journal of Chemical Research is a monthly journal which has a broad international authorship and publishes research papers and reviews in all branches of experimental chemistry.

  Recent papers have described new synthetic methods, new heterocyclic compounds, new natural products, and the inorganic chemistry of metal complexes. Now in its 34th year, the Journal of Chemical Research was established in 1977 as a joint venture by the British, French and German chemical societies and maintains the high standards set by the founding societies. Each paper is independently peer reviewed and only carefully evaluated contributions are accepted.

• Editorial Board
• Subscribe to this Title
• ingentaconnect is not responsible for the content or availability of external websites

Related content

• In this: publication
• By this: publisher
• In this Subject: Chemistry (General) ,  Organic Chemistry ,  Physical & Theoretical Chemistry
• By this author: Bera, Manindranath

Website © Publishing Technology. Article copyright remains with the publisher, society or author(s) as specified within the article.

• Terms and conditions
• Privacy policy
• Information for advertisers