The platinum-catalyzed hydroamination of ethylene with aniline is reported for the first time. Using PtBr2 as a catalyst precursor in n-Bu4PBr under 25 bar of ethylene pressure affords N-ethylaniline with 80 turnovers after 10 h at 150 °C. The reaction simultaneously produces 2-methylquinoline in ca. 10 cycles. The catalytic activity is slightly improved by increasing the reaction temperature or the ethylene pressure and strongly depends on the aniline/platinum ratio. The beneficial effects of added P(OMe)3 (2 equiv/PtBr2) or of a proton source (3 equiv/PtBr2) have also been pointed out. A gradual poisoning by N-ethylaniline has been observed, which could be minimized by using biphasic systems. The best result for the hydroamination with aniline (TON = 145 after 10 h at 150 °C) has been obtained in a biphasic system (n-Bu4PBr/decane) in the presence of C6H5NH3 + (3 equiv/PtBr2). The basicity of the arylamine has been shown to play an important role:  the lower the basicity, the higher the TON. Thus, the hydroamination of ethylene with the weakly basic 2-chloroaniline in the presence of the PtBr2/H+ catalytic system (0.3% mol) for 72 h at 150 °C yields N-ethyl-2-chloroaniline as the sole reaction product (70% yield based on the amine charged) with TON = 250. When conducted with 1% of the above catalytic system, the reaction resulted in nearly quantitative conversion of 2-chloroaniline.

In mononitrosyl complexes of transition metals two long-lived metastable states corresponding to linkage isomers of the nitrosyl ligand can be induced by irradiation with appropriate wavelengths. Upon irradiation, the N-bound nitrosyl ligand (ground state, GS) turns into two different conformations: isonitrosyl O bound for the metastable state 1 (MS1) and a side-on nitrosyl conformation for the metastable state 2 (MS2). Structural and spectroscopic investigations on [RuCl(NO)py(4)](PF(6))(2)·1/2H(2)O (py = pyridine) reveal a nearly 100% conversion from GS to MS1. In order to identify the factors which lead to this outstanding photochromic response we study in this work the influence of counteranions, trans ligands to the NO and equatorial ligands on the conversion efficiency: [RuX(NO)py(4)]Y(2)·nH(2)O (X = Cl and Y = PF(6)(-) (1), BF(4)(-) (2), Br(-)(3), Cl(-) (4); X = Br and Y = PF(6)(-) (5), BF(4)(-) (6), Br(-)(7)) and [RuCl(NO)bpy(2)](PF(6))(2) (8), [RuCl(2)(NO)tpy](PF(6)) (9), and [Ru(H(2)O)(NO)bpy(2)](PF(6))(3) (10) (bpy = 2,2'-bipyridine; tpy = 2,2':6',2"-terpyridine). Structural and infrared spectroscopic investigations show that the shorter the distance between the counterion and the NO ligand the higher the population of the photoinduced metastable linkage isomers. DFT calculations have been performed to confirm the influence of the counterions. Additionally, we found that the lower the donating character of the ligand trans to NO the higher the photoconversion yield.