X-ray crystal structure, EPR and electrochemical studies of two novel cyanonitrosylrhenates: K2[Re(NO)(CN)5]·(Phen)6·4.5H2O and K[Re(NO)(H2O)(CN)4]·(Phen)5·CH3OH·3H2O

Synthesis, crystal structure and magnetic properties of the Re(ii) complexes NBu4[Re(NO)Br4(L)] (L = pyridine and diazine type ligands)

“…Then, the solution is evaporated to ca. 5 cm 3 4)]. Complexes 1-4 were prepared by using a common synthetic procedure: 0.91 mmol of L (0.072 g of pyridine or 0.073 g of pyrazine, pyrimidine, or pyridazine) was added to a solution of NBu 4 [Re(NO)Br 4 (EtOH)] (0.060 mmol, 0.050 g) dissolved in EtOH (10 cm 3 ).…”

“…Therefore, the magnetic susceptibility for complexes 1-4 can be described taking into account the magnetic properties of only this ground Kramer's doublet considered as an effective-spin S eff = 1/2. Under an axial symmetry, one has the parallel (H∥C4) and perpendicular (H⊥C4) components of the magnetic susceptibility [eqn (3)]…”

“…The soft character of this metal ion with a d 5 configuration requires the presence of ligands containing phosphorus as donor atoms or π-binding ligands such as CN − , CO, NO or aromatic amines to provide enough stability. These complexes are prepared by different synthetic routes starting from Re(V) precursors, 2 ReO 4 − , 3 Re(III) complexes, 4 rhenium metal, 5 or even Re-Re dimers. 6 Re(II)-nitrosyl compounds constitute a group of stable complexes with interesting structural, electronic and spectroscopic properties which are the subject of a recent review.…”

“…7 In particular, the {Re(NO)} 5 fragment has been found in six-coordinate complexes forming compounds like neutral [Re(NO)X 3 L] (X = Cl and Br; L = PPh 3 , AsPh 3 , OPPh 3 and OAsPh 3 ), 2a,b,8 cationic [Re(NO)Cl(dppe)] 2+ [dppe = 1,2-bis(diphenylphosphinoethane)], 9 and anionic [Re(NO)X 4 L] − (X = Cl, Br and CN; L = H 2 O, EtOH, MeCN and pyridine). 3,10 These complexes with the {ReNO} 5 core can be formally considered as Re(II) compounds with the NO + ligand. In this way, the electronic structure should be viewed as (e) 4 (b 2 ) 1 under a tetragonal geometry.…”

The first heterobimetallic one dimensional cyano bridged nitrosyl complex containing an alkaline earth metal: synthesis, characterization and crystal structure of the complex [Sr(Phen)2(DMF)2][Fe(NO)(CN)5]

“…Though the bands should essentially be of Fe 3dp ! NO pp* transitions, the band intensities are one to two orders of magnitude less than those of [Os(NO)(NCS) 5 ] 2À [17] as well as [Re(NO)(CN) 5 ] 2À [18]. Interestingly Na 2 [Fe(NO)(CN) 5 ] AE 2H 2 O shows only two bands at 407 and 541 nm indicating that the b 2 !…”