Thio derivatives of β-diketones and their metal chelates. II. α-Substituted Monothio-β-diketones as ligands

1965 ◽  
Vol 18 (12) ◽  
pp. 1927 ◽  
Author(s):  
RKY Ho ◽  
SE Livingstone ◽  
TN Lockyer

The α-methyl substituted monothio-β-diketones, 4-mercapto-3-methylpent-3-en-2-one, MeC(SH)=C(Me)COMe, and 3-mercapto-2-methyl-1,3-diphenylprop-2-en-1-one, PhC(SH)=C(;Me)COPh, were prepared; the former was not obtained pure. The complexing ability of these ligands appears to be weaker than that of other monothio-β-diketones; this can be partly explained on the basis of steric hindrance caused by the methyl group attached to the central carbon atom. The diamagnetic complexes, Ni(MeCS=CMeCOMe)2, Co(MeCS=CMeCOMe)3, and Ni(PhCS=CMeCOPh)2 were obtained but attempts to prepare other metal complexes of these ligands were unsuccessful. The infrared spectra of the three metal chelates display four characteristic bands for which assignments are given: 1570-1540 cm-1, v(C--C); 1525-1500 cm-1, v(C-0); 1230-1223 cm-1, v(C--8); 497-458 cm-1, v(M-0).

1967 ◽  
Vol 20 (6) ◽  
pp. 1065 ◽  
Author(s):  
SHH Chaton ◽  
SE Livingstone

Complexes of 3-mercapto-1,3-diphenylprop-2-en-1-one, PhC(SH)=CHCOPh, with iron(III), cobalt(III), rhodium(III), nickel(II), palladium(II), platinum(II), copper(II), silver(I), zinc(II), cadmium(II), and mercury(II) have been prepared and characterized. Complexes of 4- mercaptopent-3-en-2-one, MeC(SH)=CHCOMe, with cobalt(III) and cadmium(II) and of ethyl thioacetoacetate, MeC(SH)=CHCOOEt, with cobalt(III) and copper(I) are also reported. The infrared spectra of the complexes of 3-mercapto-1,3- diphenylprop-2-en-1-one are discussed. The similarity of the spectra of the silver(I), cadmium(II), and mercury(II) complexes to those of the free ligand and its S-methyl derivative, PhC(SMe)=CHCOPh, indicate that in these three complexes the carbonyl oxygen of the ligand is not, or is at most weakly, coordinated to the metal ion. The assignments of the principal bands in the other metal complexes of this ligand are: 1550- 1525 cm-1, v(C-C); 1480-1458 cm-1, v(C=O); 1438-1412 cm-1, v(C=O)+δ(C-H); 1270-1260 cm-1, v(C--S); 498-437 cm-1, v(M-O); 399-376 cm-1, v(M-S).


1968 ◽  
Vol 21 (1) ◽  
pp. 103 ◽  
Author(s):  
RKY Ho ◽  
SE Livingstone ◽  
TN Lockyer

Complexes of l,l,l-trifluoro-4-mercapto-4-phenylbut-3-en-2-one, PhC(SH)= CHCOCF3, with cobalt(111), nicke1(11), palladium(11), platinum(11), copper(11), zinc(11), cadmium(11), and mercury(11) have been prepared and characterized. Their infrared spectra and the spectra of metal complexes of two other fluorinated monothio-β-diketones are discussed. Adducts of nickel (11) palladium(11), platinum(11), zinc(11), cadmium(11), mercury(11), and lead(11) complexes of the fluorinated monothio-β-diketones, RC(SH)=CHCOCF3 (R = Ph, α-thienyl, or Me), with pyridine, α-picoline, γ-picoline, 2,2'-bipyridyl, 1,l0-phenanthroline, 2,9-dimethyl-1,l0-phenanthroline, 2,2',2"-terpyridyl, or triphenylphosphine are described. Molecular weight and visible spectral measurements on PdL2(PPh3)2 (L = C4H3SC(SH)=CHCOCF3) show that in nitro- benzene and toluene solution one phosphine moiety is lost. Similarly, ZnL2 pic2 (pic = α- or γ-picoline) loses one molecule of picoline in nitrobenzene solution. The infrared data indicate that in the adducts nickel, zinc, and probably cadmium are six-coordinate and palladium, platinum, mercury, and lead are four-coordinate, while zinc is five-coordinate in the mono-adducts ZnL2 pic.


1940 ◽  
Vol 129 (857) ◽  
pp. 528-538 ◽  

The oestrogenic activity of four classes of 4 : 4’-dihydroxydiphenylmethane derivatives has been studied. Variation of activity in homologous series has been found, and maximum potencies established. The relationships between structure and maximum potency have been found parallel to those in other series of synthetic oestrogens. The effect of methyl groups attached to the aromatic rings has been investigated, and the results suggest a biological connexion between these groups and other groups on the central carbon atom, since the effects vary in marked manner with alteration of the chain length of the central groups.


2006 ◽  
Vol 84 (5) ◽  
pp. 771-781 ◽  
Author(s):  
Cina Foroutan-Nejad ◽  
Gholam Hossein Shafiee ◽  
Abdolreza Sadjadi ◽  
Shant Shahbazian

In this study, a detailed topological charge density analysis based on the quantum theory of atoms in molecules (QTAIM) developed by Bader and co-workers, has been accomplished (using the B3LYP method) on the CB62– anion and three planar isomers of the C3B4 species, which had been first proposed by Exner and Schleyer as examples of molecules containing hexacoordinate carbon atoms. The analysis uncovers the strong (covalent) interactions of boron atoms as well as the "nondirectional" interaction of central carbon atom with those peripheral atoms. On the other hand, instabilities have been found in the topological networks of (B6C)2– and B4C3(para) species. A detailed investigation of these instabilities demonstrates that the topology of charge density has a floppy nature near the equilibrium geometries of the species under study. Thus, these species seems to be best described as complexes of a relatively concrete ring containing boron or carbon atoms and a central carbon atom that is confined in the plane of the molecule, but with nondirectional interactions with the surrounding atoms.Key words: hypervalency, hexacoordinate carbon, quantum theory of atoms in molecules, charge density analysis, ab initio methods.


1969 ◽  
Vol 47 (6) ◽  
pp. 1083-1086 ◽  
Author(s):  
D. S. Sethi ◽  
G. C. Joshi ◽  
D. Devaprabhakara

The present investigation demonstrates the hydroboration of 1,2-nonadiene, phenylpropadiene, 3-phenyl-1,2-butadiene, 4,5-nonadiene, and tetramethylallene with disiamylborane. All the allenes except tetramethylallene underwent 100% conversion. Examination of the products indicated preferential electrophilic attack of boron on the least substituted terminal carbon atom in the case of 1,2-nonadiene, phenylpropadiene, 3-phenyl-1,2-butadiene, and on the central carbon atom in 4,5-nonadiene. In tetramethylallene boron, attack was exclusively on the central carbon atom. These results have been explained in terms of steric effects on a four-centered transition state.


1976 ◽  
Vol 29 (6) ◽  
pp. 1209 ◽  
Author(s):  
SE Livingstone ◽  
JH Mayfield ◽  
DS Moore

Paramagnetic adducts of the nickel(11) chelates of the fluorinated monothio-β-diketones RC(SH)=CHCOCF3 (R = β-naphthyl, p-ClC6H4, m-ClC6H4, m-BrC6H4, m-MeC6H4, 3,4-Cl2C6H3) have been obtained with pyridine, y-picoline, 2,2'-bipyridyl, and 1,l0-phenanthroline. They are of the type NiL2(base)2 (L = RCS=CHCOCF3; base = py, γpic, �bpy, �phen). With 2,2',2"-terpyridyl two types of adduct were isolated: (a) mononuclear NiL2(trpy) and (b) trinuclear Ni3L6(trpy)2. The infrared spectra of all the adducts display v(C-O) in the range 1552-1580 cm-l; this band is characteristic of a bidentate monothio-β-diketonato ligand. The spectra of the mononuclear terpyridyl adducts display in addition a v(C=O) band at c. 1650 cm-1, indicating that one carbonyl group is not coordinated.


1966 ◽  
Vol 19 (7) ◽  
pp. 1179 ◽  
Author(s):  
RKY Ho ◽  
SE Livingstone ◽  
TN Lockyer

Metal chelates of 1,1,1-trifluoro-4-mercapto-4-(2-thienyl)but-3-en-2 one, C4H3SC(SH)=CHCOCF3 (TTMBH), and 1,1,1-trifluoro-4-mercaptopent-3-en-2-one, MeC(SH)=CHCOCF3 (TMPH) have been prepared. Inner complexes of both TTMBH and TMPH were obtained with cobalt(III), nicke1(II), palladium(11), platinum(II), zinc(II), cadmium(11), mercury(11), and lead(II); they are readily soluble in organic solvents. TTMBH gives the spin-free complex Fe(TTMB)3, the copper(II) complex Cu(TTMB)2, and the μ-dioxo-bridgedvanadium(1V) compound V2O2(TTMB)4. Iron(III) and copper(II) oxidize TMPH to the disulphide (TMP)2; however, a polymeric copper(I) complex Cu(TMP) was isolated. The complexing ability of TMPH appears to be weaker than that of TTNBH.


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