An-Najah Staff

The novel (ether-phosphine)palladium(II) complexes such as Cl2Pd(h1-Ph2PCH2CH2OCH3)2 2, [Pd(h2- Ph2PCH2CH2OCH3)2]+22BF4 - 3 and [Pd(h1-Ph2PCH2CH2OCH3)2diamine]+22BF4 - 4L1-4L4 (Scheme1) have been obtained by reaction of [PdCl2(NCCH3)2 or PdCl2(NCPh)2] with two equimolar amounts of Ph2PCH2CH2OCH3 to produce complex 2. The dicationic complex 3 was produced by treating complex 2 with slightly excess amount of two equivalent of AgBF4 in CH2Cl2. Due to the hemilabile character, the (ether)oxygen atom of the ether-phosphine ligand immediately occupied the vacant coordination sites which created by chloride abstracted agent (AgBF4) and avoided complex decomposition. Several diamines were served as an incoming ligands, the (ether)oxygen atom can easily be displaced by these diamines to prepare complexes 4L1-4L4 in very good yields. These complexes were characterized by NMR, IR, and mass spectroscopy as well as by elemental analyses. Because of the ring contribution of the chemical shift the dissociation and association (open and close mechanism) of the weak donor can be studied by 31P{1H} NMR spectroscopy at room temperature.

C33H40Cl2N2P2Ru, triclinic, P1 (no. 2), a = 9.870(1) Å, b = 13.044(1) Å, c = 14.446(3) Å, + = 110.86(1)°, * = 100.55(1)°, & = 107.657(9)°, V = 1565.2 Å3, Z = 2, Rgt(F) = 0.028, wRref(F2) = 0.067, T = 173 K.

The hemilability of the ether-phosphine ligand [Ph2PCH2CH2OMe] was recorded during complexes 1 and 2 synthesis. The structures of both 1 and 2 have been deduced from elemental analysis, IR, EXAF, FAB-mass spectrometry, 1H, 13C{1H} and 31P{1H} NMR spectroscopy. One of the chloride atoms in 1 was abstracted using AgOTf reagent to prepare the mono-cationic O-Ru-P closed 2. By treatment complex 2 with excess amount of NH4Cl in 2-propanol complex 1 was re-prepared. FAB-MS, EXAF and 31P{1H}-NMR served to monitor the hemilability of the ether-phosphine in 1 and 2 at RT.

An investigation into the potential ruthenium(II) 1-3 complexes of type [RuCl2(P)2(N)2] using triphenylphosphine and 1,3-bis-diphenylphosphinepropane and 3-(triethoxysilyl)propylamine has been carried out at room temperature in dichloromethane under an inert atmosphere. The structural behaviors of the phosphine ligands in the desired complexes during synthesis were monitored by 31P{1H}-NMR. The structure of complexes 1-3 described herein has been deduced from elemental analyses, infrared, FAB-MS and 1H-, 13C- and 31P-NMR spectroscopy. Xerogels X1-X3 were synthesized by simple sol-gel process of complexes 1-3 using tetraethoxysilane as co-condensation agent in methanol/THF/water solution. Due to their lack of solubility, the structures of X1-X3 were determined by solid state 13C-, 29Si- and 31P-NMR spectroscopy, infrared spectroscopy and EXAFS.

Syntheses of four new ruthenium(II) complexes of the [RuCl2(P)2(N)2] type using 2-(diphenylphosphino)ethyl methyl ether (P~O) as ether-phosphine and triphenylphosphine (PPh3) as monodentate phosphine ligands in the presence of [3-(2-aminoethyl)aminopropyl]trimethoxysilane as diamine co-ligand are presented for the first time. The reactions were conducted at room temperature and under an inert atmosphere. Due to the presence of the trimethoxysilane group in the backbone of complexes 1 and 2 they were subjected to an immobilization process using the sol-gel technique in the presence of tetraethoxysilane as cross-linker. The structural behavior of the phosphine ligands in the desired complexes during synthesis were monitored by 31P{1H}-NMR. Desired complexes were deduced from elemental analyses, Infrared, FAB-MS and 1H-, 13C- and 31P-NMR spectroscopy, xerogels X1 and X2 were subjected to solid state, 13C-, 29Si- and 31P-NMR spectroscopy, Infrared and EXAF. These complexes served as hydrogenation catalysts in homogenous and heterogeneous phases, and chemoselective hydrogenation of the carbonyl function group in trans-4-phenyl-3-butene-2-al was successfully carried out under mild basic conditions.

Neutral complex 1 and mono-cationic complex 2 were made available using Ph2PCH2CH2OCH3 and 1,2-diphenyl-1,2-ethanediamine ligands. One of the chloride atoms in complex 1 was abstracted by AgOTf to prepare the mono-cationic O–Ru–P closed complex 2. The hemilability of hybrid ether-phosphine ligand in such complexes was monitored by 31P{1H} NMR and confirmed by X-ray single crystal. XRD structure of complex 2 was found to be a Trigonal crystal system with P3 space group and Z = 6.