Stereochemistry of six coordinate organotin(IV) compounds with bidentate ligands

1979 ◽  
Vol 57 (17) ◽  
pp. 2223-2229 ◽  
Author(s):  
J. S. Tse ◽  
T. K. Sham ◽  
G. M. Bancroft

Extended ligand–ligand repulsion calculations have been applied to a number of six coordinate organotin complexes of the type RR′Sn(bidentate)2 (R, R′ = Me, Ph, Cl). Qualitatively, the calculations readily predict the decrease in the R—Sn—R′ angle with decrease in bite size of the bidentate ligand. The steric calculations are generally successful in predicting both the cis–trans preference of the R groups and the bond angles about the Sn atom. For the Me2Sn complexes, electronic effects (as expressed by Bent's rule) sometimes have to be used in conjunction with the steric calculations to rationalize the observed stereochemistry.

2017 ◽  
Vol 73 (11) ◽  
pp. 1739-1742 ◽  
Author(s):  
Atsuya Koizumi ◽  
Takuya Hasegawa ◽  
Atsushi Itadani ◽  
Kenji Toda ◽  
Taoyun Zhu ◽  
...  

In the title complex, diaqua(1H-imidazole-κN3)(nitrato-κ2O,O′)bis(4-oxopent-2-en-2-olato-κ2O,O′)lanthanum(III), [La(C5H7O2)2(NO3)(C3H4N2)(H2O)2], the La atom is coordinated by eight O atoms of two acetylacetonate (acac) anions acting as bidentate ligands, two water molecule as monodentate ligands, one nitrate anions as a bidentate ligand and one N atom of an imidazolate (ImH) molecule as a monodentate ligand. Thus, the coordination number of the La atom is nine in a monocapped square antiprismatic polyhedron. There are three types of intermolecular hydrogen bonds between ligands, the first involving nitrate–water O...H—O interactions running along the [001] direction, the second involving acac–water O...H—O interactions along the [010] direction and the third involving an Im–nitrate N—H...O interaction along the [100] direction (five interactions of this type). Thus, an overall one-dimensional network structure is generated. The molecular plane of an ImH molecule is almost parallel to that of a nitrate ligand, making an angle of only 6.04 (12)°. Interestingly, the ImH plane is nearly perpendicular to the planes of two neighbouring acac ligands.


Inorganics ◽  
2019 ◽  
Vol 7 (12) ◽  
pp. 142
Author(s):  
Micol Pasquali ◽  
Emilija Janevik-Ivanovska ◽  
Adriano Duatti

The purpose of this work was to further expand the chemistry of mixed technetium nitrido-peroxo complexes, a still poorly explored class of compounds containing the Tc(VII) moiety, [99gTc][Tc(N)(O2)2]. A number of novel complexes of the formula [99gTc][Tc(N)(O2)2(L)] with bidentate ligands (L) (where L = deprotonated alanine, glycine, proline) were prepared by reacting a solution of nitrido-technetic(VI) acid with L in the presence of a source of H2O2. Alternatively, the complex [99gTc][Tc(N)(O2)2X]− (X = Cl, Br) was used as a precursor for substitution reactions where the halogenide ion was replaced by the bidentate ligand. The new complexes were characterized by elemental analysis and mass spectroscopy. The preparation of the analogous [99mTc][Tc(N)(O2)2] moiety, radiolabeled with the metastable isomer Tc-99m, was also studied at a no-carrier-added level, using S-methyl-N-methyl-dithiocarbazate as the donor of the nitrido nitrogen atoms.


1975 ◽  
Vol 30 (9-10) ◽  
pp. 751-754 ◽  
Author(s):  
O. P. Pachauri ◽  
J. P. Tandon

Studies of the interaction between 1:1 Th(IV)-DTPA chelate (where DTPA = diethylenetriaminepentaacetic acid) with certain bidentate ligands, such as salicylic acid (SA), 5-sulphosalicylic acid (SSA) and 8-hydroxy quinoline-5-sulphonic acid (HQSA) have been carried out potentiometrically. The nature of the titration curves indicates that the bidentate ligand is added stepwise to the initially formed metal diethylenetriaminepentaacetate. The formation constants (log KMAB) of the resulting 1:1:1 mixed ligand derivatives have been determined at 30 ± 1 °C and μ = 0.1 (KNO3). The order of stability in terms of the secondary ligand has been found to be SA > SSA > HQSA.


1968 ◽  
Vol 21 (7) ◽  
pp. 1757 ◽  
Author(s):  
AJ Canty ◽  
GB Deacon

The complexes, C6F5HgXL2 [X = Br or C1; L2 = 2,2'-bipyridyl (bipy), 1,l0-phenanthroline (phen), 3,4,7,8-tetramethyl-1,l0-phenanthroline (tmp), or 2,9-dimethyl-1,l0-phenanthroline (dmp)], C6Cl5HgClL2 (L, = phen, tmp, or dmp), and PhHgClL2 (L2 = phen or tmp), have been prepared, but attempts to prepare PhHgCl bipy or complexes of phenylmercuric bromide were unsuccessful. Evidence that the complexes contain four coordinate mercury has been obtained from infrared spectroscopy. All complexes, except C6Cl5HgCl phen, C6Cl5HgCl dmp, and PhHgCl tmp, undergo complete or partial disproportionation reactions, 2RHgXL2 → L2HgX2 +R2HgL2 (or R2Hg + L2), in boiling benzene. Although disproportionation or low solubility precludes solution studies on the majority of the derivatives, it has been shown that C6F5HgX dmp complexes are monomeric in acetone and that PhHgCl phen undergoes dissociation, PhHgCl phen + PhHgCl + phen, in this solvent. Four-coordinate complexes of mercuric halides with neutral ligands, L,HgX, (L = a neutral unidentate or L, = a neutral bidentate ligand; X = C1, Br, or I), are well kno~n,l-~ but analogous complexes of organomercuric halides, viz. RHgXL,, were unknown prior to this investigation. Reactions of organomercuric halides with ligands generally result in disproportionation, the corresponding diorganomercurial and mercuric halide complex being f~rmed.~-~ In some cases intermediate complexes RHgL+X- have been i~olated~,~ or detected in soluti~n,~-~~ and a 1 : 1 complex of unknown structure between pyridine and cis-2- * Part VI, J. organomet. Chem., in press. Preliminary communications for Part VII: Canty, A. J., Deacon, G. B., and Felder, P. W., Inorg. nzlcl. Chem. Lett., 1967,3,263; Deacon, G. B., and Canty, A. J., Inorg. %ucl. Chem. Lett., 1968, 4, 128. t Chemistry Department, Monash University, Clayton, Vie. 3168. Evans, R. C., Mann, F. G., Peiser, H. S., and Purdie, D., J. chem. Soc., 1940, 1209. Cass, R. C., Coates, G. E., and Hayter, R. G., J. chem. Soc., 1955, 4007. Coates, G. E., and Ridley, D., J. chem. Soc., 1964, 166. Coates, G. E. "Organometallic Compounds." 2nd. Edn, pp. 78-82. (Methuen: London 1960.) Seyferth, D., and Towe, R. H., Inorg. Chem., 1962, 1, 185. Coates, G. E., and Lauder, A., J. chem. Soc., 1965, 1857. Brodersen, K., Chem. Ber., 1957, 90, 2703. Schwarzenbach, G., and Schellenberg, &I., Helv. chim. Acta, 1965, 48, 28. Goggin, P. L., and Woodward, L. A., Trans. Faraday Soc., 1962, 58, 1495. Dessy, R. E., Budde, W. L., and Woodruff, C., J. Am. chem. Soc., 1962, 84, 1172. Aust. J. Chem., 1968, 21, 1757-67


1981 ◽  
Vol 34 (10) ◽  
pp. 2177 ◽  
Author(s):  
AJ Finney ◽  
MA Hitchman ◽  
DL Kepert ◽  
CL Raston ◽  
GL Rowbottom ◽  
...  

The crystal structures of the title compounds are reported. In all cases, the coordination sphere of the nickel atom comprises three bidentate ligands. In (1), [Ni(bpy)2(O2N)] NO3, (Ni-N) is 2.M2 � although there are small differences between those nitrogen atoms trans to the nitrite oxygen atoms and the other two. (Ni-O) is 2.12 �. In (2), [Ni(bpy)3] NO2/NO3,xH2O, and (3), [Ni(bpy)3]- SO4,7.5H2O, a redetermination, Ni-N is shown to be c. 2.09 �; serious disorder is present among the non-cationic components of (2), precluding a definite assignment of stoichiometry.


RSC Advances ◽  
2019 ◽  
Vol 9 (4) ◽  
pp. 2002-2010 ◽  
Author(s):  
Masanari Hirahara ◽  
Hiroki Goto ◽  
Rei Yamamoto ◽  
Masayuki Yagi ◽  
Yasushi Umemura

Introduction of a chloro substituent to the bidentate ligand of ruthenium aqua complexes enhanced photoisomerization and thermal back-isomerization.


Synthesis ◽  
2017 ◽  
Vol 49 (16) ◽  
pp. 3726-3730
Author(s):  
Hui Lv ◽  
Xu-Mu Zhang ◽  
Xu Deng ◽  
Yu-Qing Guan ◽  
Ning-Ning Huo ◽  
...  

An efficient and modular synthetic route to the bidentate C3*-TunePhos was developed, which allowed tunable steric and electronic effects of the ligands. This novel chemical technology highlights a versatile C3*-dibromodiphenyl intermediate that was accomplished by in situ Grignard exchange and subsequent Cu(II)-mediated intra­molecular oxidative radical coupling process. It is worth noting that this advanced intermediate not only could be easily prepared by a diverse array of C3*-TunePhos-type ligands, but also could be used to facile synthesis of other novel type of N,S-centered bidentate ligands.


Molecules ◽  
2021 ◽  
Vol 26 (19) ◽  
pp. 5806
Author(s):  
Liang Liu ◽  
Hui Chen ◽  
Zhenqiang Yang ◽  
Junnian Wei ◽  
Zhenfeng Xi

Copper-catalyzed and organocopper-involved reactions are of great significance in organic synthesis. To have a deep understanding of the reaction mechanisms, the structural characterizations of organocopper intermediates become indispensable. Meanwhile, the structure-function relationship of organocopper compounds could advance the rational design and development of new Cu-based reactions and organocopper reagents. Compared to the mono-carbonic ligand, the C,N- and C,C-bidentate ligands better stabilize unstable organocopper compounds. Bidentate ligands can chelate to the same copper atom via η2-mode, forming a mono-cupra-cyclic compounds with at least one acute C-Cu-C angle. When the bidentate ligands bind to two copper atoms via η1-mode at each coordinating site, the bimetallic macrocyclic compounds will form nearly linear C-Cu-C angles. The anionic coordinating sites of the bidentate ligand can also bridge two metals via μ2-mode, forming organocopper aggregates with Cu-Cu interactions and organocuprates with contact ion pair structures. The reaction chemistry of some selected organocopper compounds is highlighted, showing their unique structure–reactivity relationships.


2021 ◽  
Vol 33 (3) ◽  
pp. 617-621
Author(s):  
Meera Gopal ◽  
Sreesha Sasi

A new series of La(III) complexes of the ligand with the general formula [La(L)2(a)3] and [La2(L)4(aa)3], (a = nitrate (1), thiocyanate (2), acetate (3) and propionate (4) ions, aa = sulphate (5), thiosulphate (6), oxalate (7) and malonate (8) ions with the ligand 4-nitrosoantipyrine (L) were synthesized and characterized using various physico-chemical studies. The primary ligand L acts as a bidentate ligand utilizing the carbonyl group and the nitroso group for bonding. The nitrate, thiocyanate, acetate and propionate ions are monovalent unidentate ligands, whereas sulphate, thiosulphate, oxalate and malonate ions are divalent bidentate ligands in the complexes 1-8. Based on spectral data and magnetic susceptibility measurements, geometry of the lanthanum(III) complexes were also proposed.


2020 ◽  
Vol 4 (2) ◽  
pp. 217-232
Author(s):  
Tunmise T Eugene-Osoikhia (Nee Adebesin) ◽  
A.O Aleem ◽  
F Ayeni

Two mixed ligands of sulfamethoxazole (SMX) with N,N donor heterocycles: 1,10-phenanthroline (phen) and 2,2′-bipyridine (bipy) metal complexes having the composition  [M(SMX)(phen)X].nH2O and  [M(SMX)(bipy)X].nH2O (where M = Zn(II) , Co(II) , Fe (II), Mn (II),Cu(II) ; X = SO4/Cl2) have been synthesised and characterised by physicochemical methods based on their solubility , metal analysis, infrared and UV-Visible techniques.  Infrared spectra data showed SMX as a bidentate ligand coordinating to the metals through the N atom of the sulfonamide group ((3195-3030cm-1)  and oxygen atom of the sulfonyl moiety (1158-1103 cm-1)  while the heterocycles also bonded as bidentate ligands through their diimine nitrogen atoms (1606-1423 cm-1).  The electronic spectra data indicated that all the metal(II) complexes were monomeric and octahedral. The in-vitro antimicrobial studies of these complexes and their ligands against environmental strains of microorganisms: Bacillus subtilis, Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli, Aspergillus niger and Candida albicans showed that SMX-phen metal complexes [M(SMX)(phen)X].nH2O are better heterocycle with zone of inhibition in the range 28-10mm to combine with SMX for the enhancement of its antimicrobial spectrum  this may be due to their more extensive aromatic ring system which gave better lipophilicity, hence aided cell membrane penetration and promoted hostile intracellular interactions leading to death of microoganisms.


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