Diorganobismuth(III) compounds with the pendant arm 2-(Me 2 NCH 2 )C 6 H 4 ligand - Isothiocyanate, trifluoracetate and nitrate Mihai G. Nema a,1 , Hans J. Breunig b, 2 , Albert Soran a, * , Cristian Silvestru a, * a Faculty of Chemistry & Chemical Engineering, Department of Inorganic Chemistry, Babes-Bolyai University, Arany Janos Nr.11, RO-400028 Cluj-Napoca, Romania b Institut für Anorganische und Physikalische Chemie, Universität Bremen, D-28334, Bremen, Germany article info Article history: Received 26 November 2011 Received in revised form 24 December 2011 Accepted 3 January 2012 Keywords: Bismuth Hypervalent Nitrate Trifluoracetate Thiocyanate Supramolecular abstract The reaction of R 2 BiCl (1) [R ¼ 2-(Me 2 NCH 2 )C 6 H 4 ] with NaSCN, AgO 2 CCF 3 or AgNO 3 (1:1 M ratio) gave R 2 BiNCS (2), R 2 BiO(O)CCF 3 (3) and R 2 BiNO 3 (4), respectively. The new compounds were investigated by IR, 1 H and 13 C NMR spectroscopies as well as mass spectrometry. The structures of 2e4 were determined by single crystal X-ray diffraction. Both nitrogen atoms from the pendant arms are involved in intra- molecular N/Bi coordination of different strength. For the isothiocyanate 2 this results in a distorted square-pyramidal (C,N) 2 BiN core. In the case of the trifluoroacetate 3 and the nitrate 4 the oxo anions can be considered as acting as monometallic biconnective (chelating) ligands [i.e. coordinated strongly asymmetric to Bi atom through oxygen atoms - BieO 2.379(12)/3.317(15) Å for 3, and 2.476(5)/3.088(5) Å for 4]. Thus, distorted pentagonal-pyramidal (C,N) 2 BiO 2 cores can be considered for both compounds. All compounds exhibit chirality due to intramolecular coordination and crystallize as racemic mixtures. Chain polymer associations, based on weak CeH$$$Ph centroid interactions between molecular units, were found in the crystals of 2 and 3. In the crystal of 4 the molecules are held together into dimer units through weak Bi$$$Ph centroid and O$$$H interactions and these dimers are further associated into layers through weak CeH$$$Ph centroid and O$$$H interactions. Ó 2012 Elsevier B.V. All rights reserved. 1. Introduction While inorganic bismuth (III) carbonates, nitrates, carboxylates and pseudohalides have a long and rich chemistry with applications in medicine [1e4] and other fields [5e8] only very little is known of their organometallic counterparts although a nitrate, EtBi(NO 3 ) 2 was reported already in the very early days of organometallic chemistry. The first structurally characterized organobismuth(III) dinitrate RBi(NO 3 ) 2 was prepared only recently using the pincer ligand 2,6-(Me 2 NCH 2 ) 2 C 6 H 3 as protecting group [9]. Few organobismuth(V) nitrates, e.g. R 4 BiNO 3 and R 3 Bi(NO 3 ) 2 , are described in the literature [10], but only the molecular structure of Ph 3 Bi(NO 3 ) 2 was reported [11]. The same lack of information applies to organobismuth(III) thiocyanates [10], only few compounds being metioned, i.e. R 2 BiSCN (R ¼ Me [12], Ph [13,14]). A single crystal X-ray diffraction study on the diphenylbismuth(III) derivative established its chain polymeric structure based on bridging thiocyanato units [14]. In contrast, several diorganobismuth(III) carboxylates, R 2 BiO 2 CR’ including trifluoracetates (R 0 ¼ CF 3 ), have been synthesized and characterized by crystallography [10b]. The use of organic groups with potential for intramolecular N/Bi interactions, e.g. pendant arm ligands as 2-(Me 2 NCH 2 )C 6 H 4 [15e28] and related derivatives [27,29e31], or “pincer” ligands like 2,6-(Me 2 NCH 2 ) 2 C 6 H 3 [9,18,26,32e36] and 2,6-[MeN(CH 2 CH 2 ) 2 NCH 2 ] 2 C 6 H 3 [37], proved to be effective in steric protection of the bismuth atom by increased coordination, as well as to reduce considerably the Lewis acidity which may lead to undesired reactions. As part of our interest on organobismuth compounds with pendant arm or “pincer” ligands we report herein the synthesis, spectroscopic characterization and crystal structures of the diorganobismuth(III) derivatives containing isothiocyanato and oxo anions, i.e. [2- (Me 2 NCH 2 )C 6 H 4 ] 2 BiX [X ¼ NCS (2), O(O)CCF 3 (3), NO 3 (4)]. 2. Results and discussion 2.1. Preparation and spectroscopic characterization The new diorganobismuth(III) derivatives 2e4 were obtained by reacting the chloride [2-(Me 2 NCH 2 )C 6 H 4 ] 2 BiCl (1) with stoichiometric * Corresponding authors. Tel.: þ40 264 593 833; fax: þ40 264 590818. E-mail addresses: hbreunig@uni-bremen.de (H.J. Breunig), cristi@ chem.ubbcluj.ro (C. Silvestru). 1 Tel.: þ40 264 593 833; fax: þ40 264 590818. 2 Fax: þ49 421 218 4042. Contents lists available at SciVerse ScienceDirect Journal of Organometallic Chemistry journal homepage: www.elsevier.com/locate/jorganchem 0022-328X/$ e see front matter Ó 2012 Elsevier B.V. All rights reserved. doi:10.1016/j.jorganchem.2012.01.011 Journal of Organometallic Chemistry 705 (2012) 23e29