The Reaction of (PPri3)2H2Cl2Ir With Phosphines: Crystal and Molecular Structures of mer-cis-(PMe2Ph)2(PPri3)-cis-Cl2HIrIII and mer-cis-(PMe2Ph)2(PPri3)-trans-Cl2HIrIII

1993 ◽  
Vol 46 (4) ◽  
pp. 529 ◽  
Author(s):  
EJ Ditzel ◽  
GB Robertson
Keyword(s):  
Phosphine Ligands ◽  
Molecular Structures ◽  
Iridium Complex ◽  
Steric Strain ◽  
Distorted Octahedral Coordination ◽  
Crystal And Molecular Structures ◽  
Distorted Octahedral ◽  
Spontaneous Reaction ◽  
Summary Data ◽  
Metal Ligand

Ambient temperature reactions of the complex (PPri3)2H2Cl2IrIV (1) with ethyl-substituted monodentate phosphine ligands are shown to yield different product types to those obtained both with methyl-substituted analogues and with phosphine itself. With the phosphines PH3 and PMe3-nPhn (n = 0, 1) there is spontaneous reaction to give the complexes mer-trans-(Ppri3)2(PR3)H-trans-Cl2IrIII, whereas with PEt3-nPhn (n = 0-2) the reaction yields mer-cis-(PR3)2(PPri3)H-trans-Cl2IrIII complexes. Under reflux the phosphines PMe3 and PMe2Ph also yield mer-cis-(PR3)2(PPri3)H-trans-Cl2IrIII complexes [PR3 = PMe3 (2), Pme2Ph (3)]. The differing course of the reactions of (1) with PMe3 and with PEt3 has permitted the synthesis of mer-(Pme3)-trans-(PPri3)(PEt3)H-trans-Cl2IrIII, the first example of an octahedral iridium complex containing three different monodentate phosphine ligands. All of the products obtained have been fully characterized by 31P and 1H n.m.r. spectroscopy. Crystal structure analyses of (3) and of its photoisomer mer-cis-(PMe2Ph)2(PPri3)H-cis-Cl2IrIII (4) have been carried out to permit comparison of the metal-ligand bonding in these complexes with that in their previously characterized, sterically less crowded, tris-PMe2Ph analogues. Summary data are as follows: (3), triclinic, Pī, a 13.414(1), b 12.062(1), c 9.077(1) Ǻ, α 79.53(1), β 88.05(1), γ 79.47(1)° [T 158�3 K], Z 2, R 0.022, Rw 0.032 (4822 reflections); (4), monoclinic, P21/n, a 19.694(1), b 15.972(1), c 9.548(1) Ǻ, β 101.45(1)° (T 293�2 K), Z 4, R 0.026, Rw 0.032 (5476 reflections). Both molecules exhibit distorted octahedral coordination of the metal atom and appreciably greater steric strain than in their (Pme2Ph)3HCl2IrIII analogues. Metal-ligand distances to the mutually trans Pme2Ph and PPri3 ligands are 2.322(1) and 2.372(1)Ǻ, respectively, for (3), and 2.359(1) and 2.406(1)Ǻ for (4), and suggest that the thermodynamically favoured cis-dichloro isomer (4) is the more strained. The preparations of the complexes (PCy3)2H2Cl2IrIV (1a) and (PCy3)2H2Br2IrIV (1b) (Cy = cyclohexyl), and their reactions with the same phosphines as used with (1), are also reported.

A Solvent-Dependent and Electrochemically Controlled Self-Assembling/Disassembling System

2003 ◽  
Vol 68 (9) ◽  
pp. 1647-1662 ◽  
Author(s):  
Valeria Amendola ◽  
Massimo Boiocchi ◽  
Yuri Diaz Fernandez ◽  
Carlo Mangano ◽  
Piersandro Pallavicini
Keyword(s):  
Equilibrium Mixture ◽  
Bidentate Ligand ◽  
Molecular Structures ◽  
The Self ◽  
Molar Ratio ◽  
Crystal And Molecular Structures ◽  
Self Assembling ◽  
Irreversible Oxidation ◽  
Irreversible Reduction ◽  
Metal Ligand

The bis-bidentate ligand R,S-1,2-diphenyl-N,N'-bis(2-quinolinemethylidene)ethane-1,2-diamine (ligand 4), containing two (iminomethyl)quinoline moieties separated by a cis-1,2-diphenylethylene spacer, forms stable complexes with both CuI and CuII. With CuII, the monomeric 1:1 complex [CuII(4)]2+ is obtained both in CH3CN and CH2Cl2. With CuI and overall 1:1 metal/ligand molar ratio, an equilibrium mixture is obtained in CH3CN, consisting of [CuI(4)2]+, [CuI2(4)2]2+ and [CuI2(4)(CH3CN)4]2+. The preponderant species is the two-metal one-ligand "open" complex [CuI2(4)(CH3CN)4]2+, in which each Cu+ cation is coordinated in a tetrahedral fashion by one (iminomethyl)quinoline unit and by two CH3CN molecules. Precipitation from the equilibrium mixture yields only crystals of [CuI2(4)(CH3CN)4](ClO4)2·2CH3CN, whose crystal and molecular structures have been determined. On the other hand, in the poorly coordinating CH2Cl2 solvent, only the dimeric helical [CuI2(4)2]2+ complex is obtained, when the overall metal/ligand 1:1 molar ratio is chosen. Addition of large quantities of acetonitrile to solutions of [CuI2(4)2]2+ in dichlorometane results in the formation of [CuI2(4)(CH3CN)4]2+, i.e. in the solvent-driven disassembling of the CuI helicate. While electrochemistry in CH3CN is poorly defined due to the presence of more than one CuI species, cyclic voltammetry experiments carried out in CH2Cl2 revealed a well defined behavior, with irreversible oxidation of [CuI2(4)2]2+ and irreversible reduction of [CuII(4)]2+ taking place at separate potentials (∆E ≈ 700 mV). Irreversibility and separation of the redox events are due to the self-assembling and disassembling processes following the reduction and oxidation, respectively.

The crystal and molecular structures of the bispyridine and 1,10-phenanthroline adducts of Bis(ethyl 3-mercaptobut-2-enoato)nickel(II)

1982 ◽  
Vol 35 (2) ◽  
pp. 331 ◽  
Author(s):  
J Sachinidis ◽  
MF Mackay ◽  
MW Grant
Keyword(s):  
Thermodynamic Data ◽  
Molecular Structures ◽  
Space Group ◽  
X Ray ◽  
Bond Lengths ◽  
Crystal And Molecular Structures ◽  
Distorted Octahedral ◽  
In Cis ◽  
Oxygen Atoms

X-ray analyses of monoclinic crystals of the bispyridine and 1,10-phenanthroline adducts of the monothioacetylacetonate complex bis(ethyl 3-mercaptobut-2-enoato)nickel(n), Ni(eosm)2,* have defined their structures. Crystals of the bispyridine adduct Ni(eosm)2,py2, C22H28N2NiO4S2, belong to the space group P21/c with a 8.865(6), b 15.758(4), c 9.136(3)Ǻ, β 109.18(4)°, Z 2. Crystals of the 1,10-phenanthroline adduct Ni(eosm)2,phen, C24H26N2NiO4S2, belong to the space group P21c with a 12.451(2), b 16.949(1), c 15 5921(2) Ǻ, β 130.97(1)°, Z 4. The structures were refined with diffractometer data measured with Cu Ka radiation to R 0.047 (1962 terms) for the bispyridine adduct and R 0.061 (3115 terms) for the phenanthroline adduct. The geometry about the nickel in each complex is distorted octahedral. The molecule of the bispyridine adduct has exact rn symmetry with the two sulfur atoms cis-equatorial and the nitrogen atoms axial. In the phenan- throline adduct, pairs of sulfur, nitrogen and oxygen atoms are in cis configurations. In the bis-pyridine adduct, the Ni-N bond lengths, 2.153(3) and 2.182(4) Ǻ, are significantly longer than those in other bispyridine adducts of nickel(II) species. It is suggested that the long Ni-N distances reflect the relative instability of the bispyridine adduct, and thermodynamic data are presented to support this.

Copper complexes of Picloram: The crystal and molecular structures of Bis(4-amino-3,5,6-trichloropyridine-2-carboxylato)aquacopper(II) dihydrate and Bis(4-amino-3,5,6-trichloropyridine-2-carboxylato)bis(pyrimidin-2-amine)copper(II)

1983 ◽  
Vol 36 (1) ◽  
pp. 183 ◽  
Author(s):  
EJ O'Reilly ◽  
G Smith ◽  
CHL Kennard ◽  
AH White
Keyword(s):  
Copper Complexes ◽  
Molecular Structures ◽  
Monoclinic Space Group ◽  
Space Group ◽  
X Ray ◽  
Crystal And Molecular Structures ◽  
Trigonal Bipyramidal ◽  
Distorted Octahedral ◽  
A Cell ◽  
Amine Ligands

The crystal structures of two copper(II) complexes of the herbicide Picloram (4-amino-3,5,6-trichloro- pyridine-2-carboxylic acid) have been determined by single-crystal X-ray diffractometry. Bis(4-amino- 3,5,6-trichloropyridine-2-carboxylato)aquacopper(II) dihydrate (1) is monoclinic, space group C2/c, with Z 4 in a cell of dimensions a 15.593(6), b 7.940(6), c 16.983(6) �, β 107.58(3)�. The structure was refined to a residual R 0.046 for 905 'observed' reflections. Complex (1) is trigonal bipyramidal with the trigonal plane consisting of oxygens from two picolinate ligands [Cu-O 1.995(5) �] and a water molecule [Cu-O 2.080(5) �]. The apical positions are occupied by pyridine ring nitrogens from the Picloram ligands [Cu-N 2.021(5) �]. Bis(4-amino-3,5,6-trichloropyridine- 2-carboxylato)bis(pyrimidin-2-amine)copper(II) (2) is monoclinic, space group P2,/c, with Z 4 in a cell of dimensions a 12.3 11(5), b 15.435(5), c 15.320(6) �, β 115.95(3)�, and gave a final R 0.059 for 2429 'observed' reflections. In complex (2), the copper(II) atom has a tetragonally distorted octahedral stereochemistry with the Picloram ring nitrogens once again occupying the two axial positions [Cu-N 2.586(7) and 2.611(7) �]. The square plane consists of two carboxylato oxygens [Cu-O 1.941(6) and 1.960(7) �] and two hetero-nitrogens from pyrimidin-2-amine ligands [Cu-N 2.048(6) and 2.054(6) �].

Reactions of RuCl(C=CHBut)(PPh3)(hC5Me5) with Tertiary Phosphites: Molecular Structure of RuCl{P(OPh)3} 2(h;-C5Me5)

1997 ◽  
Vol 50 (11) ◽  
pp. 1097 ◽  
Author(s):  
Michael I. Bruce ◽  
Ben C. Hall ◽  
Edward R. T. Tiekink
Keyword(s):  
Molecular Structure ◽  
Phosphine Ligands ◽  
Molecular Structures ◽  
Tertiary Phosphine ◽  
Crystal And Molecular Structures

Reactions between RuCl(C=CHBut)(PPh3)(η-C5Me5) and tertiary phosphites result in displacement of both vinylidene and tertiary phosphine ligands to give RuCl{P(OR)3}2(η-C5Me5) (R = Me, Ph). The crystal and molecular structures of RuCl{P(OPh)3}2(η-C5Me5) are reported.

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