(Terpyridine)(acetylacetonate)ruthenium(II) complex with a zwitterionic form of phosphoniophenylcyanamide ligand Lucinda Dudd a , Matthew Hart a , David Ring a , Elodie Sondaz a , Jacques Bonvoisin a, * , Yannick Coppel b,1 a CEMES/CNRS, Molecular Electronics Group, BP 4347, 29 rue Jeanne Marvig, F-31055 Toulouse Cedex 4, France b LCC/CNRS, UPR8241, 205 route de Narbonne, F-31077 Toulouse Cedex 4, France Received 5 June 2003; accepted 21 August 2003 Published online: 28 September 2003 Abstract The complex [Ru(tpy)(acac)(PPh 4 cyd)][PF 6 ] (where tpy: 2,2 0 :6 0 ,2 00 -terpyridine, acac: acetylacetone and PPh 4 cyd: 4-triphenyl- phosphoniophenylcyanamide) has been synthesized. It contains the zwitterionic form of the phosphoniophenylcyanamide ligand. Characterizations were carried out using IR, ES-MS, UV–Vis, electrochemistry and 1 H, 13 C and 31 P NMR spectroscopy. Ó 2003 Elsevier B.V. All rights reserved. Keywords: Ruthenium(II) complex; Cyanamide; NMR; Zwitterion; Phosphonium 1. Introduction Our previous work led to the synthesis of [Ru(tpy) (bpy)Ipcyd)] þ (where Ipcyd: 4-Iodophenylcyanamide anion) [1]. The strategy was to find good candidates giving a strong interaction between distant paramag- netic sites following the building blocks approach [2]. Unfortunately, the desired paramagnetic form of the complex (Ru(III) state) could not be reached because of the proximity in energy of the ruthenium and cyanamide orbitals making the ruthenium impossible to oxidize. In the present work, we have replaced the bipyridine ligand with a better donor group such as acetylacetone which has shown its capacity to tune the redox potential of ruthenium complexes [3]. The Iodophenylcyanamide li- gand was chosen for two reasons: firstly, because of the NCNÕs efficiency to mediate electronic or magnetic in- teractions [4] and secondly, because iodide has proven to be an efficient reaction center for further metal-catalyzed coupling reactions [5]. Here, we show the successful synthesis of a new neutral building block [Ru(tpy)(acac) Ipcyd)] and an unexpected result, the obtaining of [Ru(tpy)(acac)(PPh 4 cyd)] þ which contains a zwitterionic form of the phosphoniophenylcyanamide ligand. This last is shown in Scheme 1. As well as the synthetic work, we also present here the characterization of the complex through a series of pro- cedures including, UV–Vis spectroscopy, mass spec- trometry, electrochemistry and detailed NMR. 2. Experimental 2.1. Materials All chemicals and solvents were reagent grade or better. [Ru(tpy)Cl 3 ] [6] and 4-Iodophenylcyanamide (IpcydH) [1] were prepared according to literature pro- cedures. Weakly acidic Brockmann I type alumina (Al- drich) was used. All manipulations were carried out under an atmosphere of dry Ar. 2.2. Physical measurements Electrospray spectra (positive mode) were obtained with a Perkin–Elmer Sciex (Nermag R10-R10). IR were Inorganic Chemistry Communications 6 (2003) 1400–1405 www.elsevier.com/locate/inoche * Corresponding author. Tel.: +33-5-62-25-78-52; fax: +33-5-62-25- 79-99. E-mail address: jbonvoisin@cemes.fr (J. Bonvoisin). 1 Tel.: +33-5-61-17-54-28; fax: +33-5-61-30-03. 1387-7003/$ - see front matter Ó 2003 Elsevier B.V. All rights reserved. doi:10.1016/j.inoche.2003.08.016