The modular syntheses of C3-symmetric tris(ferrocenyl)arene-based tris-phosphanes and their homotrinuclear gold(I) complexes are reported. Choosing the arene core allows to fine-tune the exact oxidation potentials and thus to tailor the...

2,4,6-Tris(1-diphenylphosphanyl-1'-ferrocenylene)-1,3,5-triazine (1)c oordinates all three coinage metal(I) ions in a1 :1 tridentate coordination mode. The C 3 -symmetric coordination in both solids tate and solution is stabilisedb ya nu ncommon cation-p interaction between the triazine core and the metal cation. Intramolecular dynamic behaviour was observed by variable-temperature NMR spectroscopy.T he borane adduct of 1, 1BH 3 , displays four accessible oxidation states, suggesting complexes of 1 to be intriguing candidates for redox-switchable catalysis. Complexes 1Cu, 1Ag,a nd 1Au display a more complicated electrochemical behaviour,a nd the electrochemical mechanism was studied by temperatureresolved UV/Vis spectroelectrochemistry and chemical oxidation.Scheme1.Preparation of tris-phosphane 1 andits corresponding coinage metal complexes 1Cu, 1Ag,and 1Au.I solated yields are given in brackets. À-basedS E; arrowsd enote the startingp otentialand initial scan direction at 100 mV s À1 .The secondo fthreeconsecutively measured cycles is shownifnot noted otherwise. Bottomr ight: Equilibrium between two coordination isomersof1Cu in solution.

A facile two-step synthesis of bis(1-methylhydrazinyl)pyrimidine from pyridine-2-carbaldehyde and 2diphenylphosphanylbenzaldehyde gave access to the new asymmetric ligand 1. The phosphane selectively guides Pd II into the softer tridentate N,N,P pocket, yielding monometallic complex 2. A second reaction with a 3d transition metal complex precursor (groups 7 to 12) fills the vacant N,N,N pocket and thus provides a variety of heterobimetallic complexes of the type Pd II /M II (M = Mn (3), Fe (4), Co (5), Ni (6), Cu (7), Zn ( 8)). Single-crystal X-ray diffraction studies were performed for all complexes. The assembly of μ 2 -chlorido-bridged dimers was observed for complexes 5−7 in the solid state, while DOSY NMR experiments have shown that 5−7 are unbridged monomers in solution. As an exception, Fe II prefers to form the homoleptic meridional complex [Fe{PdCl(1)} 2 ](OTf) 4 (4). The electrochemical behavior and the effective magnetic moment in solution were investigated for all complexes by cyclic voltammetry and Evans method, respectively. Experimental UV/vis results were interpreted by performing TD-DFT calculations on 1, 2, and 3.

Two distorted square-planar RhI complexes (1 and 2) were obtained from [{RhCl(η4-cod)}2] and the respective P,N ligands.