Coordination complexes of acetylene diphosphines. II. Diphosphine bridged palladium(II) and platinum(II) derivatives

1969 ◽  
Vol 47 (14) ◽  
pp. 2573-2578 ◽  
Author(s):  
A. J. Carty ◽  
A. Efraty

Complexes of the type (MX2)2(DPPA)2 (M = Pd, Pt; X = Cl, Br, I, SCN; DPPA = bis(diphenylphosphino)acetylene) have been prepared and characterized. Raman, infrared, and molecular weight data have been used to show that the structures are binuclear with bridging bis(diphenylphosphino)acetylene groups. The infrared spectra of the compounds [M(SCN)2]2(DPPA)2 are suggestive of the presence of both N and S bonded thiocyanate within the same molecule.

1962 ◽  
Vol 40 (12) ◽  
pp. 2234-2242 ◽  
Author(s):  
Roland Rivest

The following coordination complexes of titanium (IV) have been prepared: TiCl4•2CO(NH2)2, TiCl4•CO(NHCH3)2, TiCl4•2CO(NHCH3)2, 2TiCl4•2NH2CON(C6H5)2, 2TiCl4•2CO(NHC6H5)2 TiCl4•2CS(NH2)2, 2TiCl4•CS(NHC2H5)2, 2TiCl4•NH2CSN(C6H5)2, and 2TiCl4•CS(NHC6H5)2; their infrared spectra have been measured and their molecular weight determined. For urea and its derivatives the coordination to titanium (IV) is always through the oxygen atom. The phenyl derivatives of urea led to dinuclear complexes which were best explained by assuming halogen bridging between the titanium atoms. Thiourea and its derivatives gave complexes in which coordination occurred through one of the nitrogens in the case of thiourea and through both nitrogens in the case of the derivatives. Halogen bridging was again assumed to explain the formation of the dinuclear complexes.


1961 ◽  
Vol 39 (11) ◽  
pp. 2343-2352 ◽  
Author(s):  
Ernest Rivet ◽  
Real Aubin ◽  
Roland Rivest

Co-ordination complexes between diesters of α,ω-dicarboxylic acids and titanium tetrachloride, tin tetrachloride, and zirconium tetrachloride have been prepared. The analytical results, the infrared spectra, the melting points, and the molecular-weight determinations indicate that for the titanium and zirconium complexes, two types of complexes are obtained, one having a general formula MX4•1 diester in which chelate rings from five to nine atoms are formed and the other one, 2MX4•1 diester in which there are two 4-membered rings per complex molecule. With tin tetrachloride only one type of complex is formed, which has two tin tetrachlorides and two diesters per complex molecule.


1978 ◽  
Vol 31 (3) ◽  
pp. 527 ◽  
Author(s):  
RJ Bertino ◽  
GB Deacon ◽  
JM Miller

The complexes RHg(ox) (R = C6F5, p-HC6F4, or p-MeOC6F4; ox = quinolin-8- olate) have been prepared by reaction of thallous quinofin-8-olate with the appropriate organomercuric chlorides whilst PhHg(ox or meox), MeHg(ox),H2O, and MeHg(meox) (meox = 2-methylquinolin-8-olate) have been obtained from phenyl- or methyl-mercuric hydroxide and quinolin-8-ol or 2-methyl-quinolin-8-ol. Although MeHg(ox),H2O was readily dehydrated, the water could not be displaced by ligands (e.g. Ph3PO, Me2SO). Chelation of the quinolin-8-olate ligands (rather than unidentate O- bonding) was established for all complexes by ultraviolet/visible spectroscopy. Molecular weight data indicated that all complexes except MeHg(ox) and MeHg(ox),H2O are partly associated in benzene, chloroform and/or carbon tetrachloride [K(2 monomer ↔ dimer) in the range 1-40 mol-1 dm3]; this suggests an associated structure in the solid state. Some supporting evidence for associated structures was obtained by mass spectrometry. The structural conclusions are discussed in the light of crystal structures of PhHg(ox) and PhHg(meox) carried out in a concurrent investigation.


1970 ◽  
Vol 23 (10) ◽  
pp. 1989 ◽  
Author(s):  
DR Dakternieks ◽  
DP Graddon

A series of bis(O,O-dialkyldithiophosphato)zinc(11) complexes, ZnL2 (LH = (R0)2PS2H; R = Et, Pri, Bu, Bui, Bus, cyclohexyl), has been isolated. Pyridine adducts ZnL2(py)2 (R = Et, Pr, Pri, Bui) and ZnL2(py) (R = Pr, Pri, Bui) have also been obtained. Basic complexes ZnO,3ZnL2 (R = Et, Pr) have been isolated. Molecular weight data show that ZnL2 associates in benzene. When R = Pri 2ZnL2 ↔ Zn2L4 ΔG0c -6kJ mol-1 The adducts ZnL2(py) are stable. Adducts ZnL2(py)2 dissociate in benzene; when R = Pr ZnL2(py) + PY + ZnL2(py)2 ΔG0c-7kJmol-1 (ΔG0 calculated from molal concentrations). Infrared data cannot distinguish between chelate, bridging, and unidentate PS2 groups. Co-crystallization of ZnL2(py)2 and XiL2(py)2 could not be achieved, suggesting ZnL2(py)2 is cis-octahedral.


1970 ◽  
Vol 48 (16) ◽  
pp. 2488-2493 ◽  
Author(s):  
R. G. Goel ◽  
H. S. Prasad

Triphenylbismuth(V) acid derivatives of the type, Ph3BiX2, where X = halide, nitrate, cyanate, acetate, haloacetate, or cyanoacetate have been prepared. Infrared spectra (4000 to 200 cm−1 region), electrical conductances, and molecular weights of these compounds have been studied to elucidate their structural features and chemical constitution. The molecular weight and conductance data show that these compounds behave as molecular species in benzene or nitromethane. The infrared spectroscopic results also indicate non-ionic five-coordinate structures. Bi—X stretching frequencies have been assigned for the difluoride, dichloride, dinitrate, dicyanate, and diacetate. These frequencies occur in the region 410–240 cm−1.


1966 ◽  
Vol 44 (8) ◽  
pp. 895-898 ◽  
Author(s):  
Gopal Narain

Coordination complexes of copper(II) acetate, ammonia, aliphatic amines, and pyridine have been prepared. Molecular formulae on the basis of percentage of constituent elements were found to be Cu(OAc)2(am)2, where OAc represents acetate ion and am any amine used. Conductivity measurements in nitrobenzene and formamide indicate that the complexes are nonelectrolytes and thus it is suggested that acetate ions are also coordinated. Molecular weight measurements in the same solvents confirm this. Visible absorption measurements in formamide show a single band at about 635 mμ.


1942 ◽  
Vol 15 (3) ◽  
pp. 446-451
Author(s):  
G. Gee

Abstract The molecular weight data reported in Part II depend on the assumption that the values obtained by extrapolating osmotic pressure measurements to infinite dilution represent true molecular weights. This point of view has been strongly criticized, particularly by Pummerer and his coworkers, according to whom rubber normally exists in solution in the form of micelles comprising more or less well-defined aggregates containing a considerable number of chemical molecules. The- osmotic “molecular weight” is then regarded as the weight of an average micelle. If they exist, these micelles may be important in determining both the chemical and physical behavior of rubber, for we should clearly expect the bonds by which the chemical molecules are bound into micelles to be weaker than those within the molecules. It may be noted that it has been shown elsewhere that the physical properties of a series of rubber fractions are closely related to their osmotic and viscosity molecular weights. Since, according to the micellar theory, these fractions can differ only in micelle size, their mechanical behavior must, from this viewpoint, be determined by the size of the micelles, which must therefore remain intact during mechanical deformation of the rubber. It is the object of the present paper to examine in more detail the basis of the micellar theory, and especially to offer an interpretation of the results of the East method, on which Pummerer's arguments are mainly based.


1962 ◽  
Vol 40 (12) ◽  
pp. 2243-2248 ◽  
Author(s):  
Sumer Chand Jain ◽  
Roland Rivest

Coordination complexes between titanium tetrachloride and some chlorine-substituted monoesters have been prepared.Infrared spectra of these complexes and their melting points indicate that the strength of the coordination bonds decreases as the number of chlorines increases in the acid radical. When the substitution is in the alkyl radical, it is possible to prepare complexes of the formula TiCl4•2 ester, since the chlorine substitution decreases the basic properties of the oxygen of the ether group in the ligand.


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