Alkylaluminum complexes containing pyridyl amido ligands. Syntheses and characterization of AlMe2[N(CH2-2-Py)2], Al2Me5[N(CH2-2-Py)2], and Al2Me4[2,3,5,6-tetra(2-pyridyl)piperazyl], an unusual carbon–carbon bond coupling product

1996 ◽  
Vol 74 (11) ◽  
pp. 2032-2040 ◽  
Author(s):  
Steven J. Trepanier ◽  
Suning Wang

The reactions of AlMe3 with di(2-pyridylmethyl)amine have been investigated. Two new complexes, AlMe2[N(CH2-2-Py)2] (1) and Al2Me4[2,3,5,6-tetra(2-pyridyl)piperazyl] (3), were obtained as the major and the minor product, respectively, from the reaction of AlMe3 with di(2-pyridylmethyl)amine in a 1:1 ratio in toluene at 23 °C. The reaction of AlMe3 with di(2-pyridylmethyl)amine in a 2:1 ratio yielded a dinuclear complex Al2Me5[N(CH2-2-Py)2] (2). These complexes were fully characterized by NMR, and elemental and single-crystal X-ray diffraction analyses. Crystal data: 1, C14H18N3Al, monoclinic, P21/m, a = 7.568(2), b = 7.340(1), c = 13.120(8) Å, β = 104.17(3)°, V = 706.6(4) Å3, Z = 2; 2, C14H27N3Al2, triclinic, [Formula: see text], a = 8.422(1), b = 16.711(6), c = 7.659(1) Å, α = 91.94(2)°, β = 113.08(1)°, γ = 85.17(2)°, V = 988.2(4) Å3, Z = 2; 3, C28H32N6Al2, monoclinic, P21/c, a = 7.522(8), b = 15.841(8), c = 11.584(4) Å, β = 98.53(5)°, V = 1365(1) Å3, Z = 2. Compound 1 is a mononuclear complex with the aluminum atom in an approximately trigonal bipyramidal geometry and the amido nitrogen atom in a trigonal planar geometry. Compound 2 contains two aluminum centers bridged by an amido nitrogen atom where one of the aluminum atoms has a tetrahedral geometry while the other has a trigonal bipyramidal geometry. The dinuclear compound 3 can be described as the result of two unusual C—C bonds coupling between the methylene carbon atoms of two molecules of 1. The aluminum coordination environment in 3 is similar to that of 1. Key words: aluminum, amide, pyridyl, 2,3,5,6-tetra(2-pyridyl)piperazine, structure.

2020 ◽  
Vol 44 (11-12) ◽  
pp. 721-726
Author(s):  
Xiaolong Wang ◽  
Xian Yue ◽  
Long Deng

Two novel mononuclear Zn(II) complexes, [ZnL1Cl2] (1) (L1=( E)-3-(4-(2,2′:6′,2″-tripyridyl)-4′-styryl)-7-diethylaminocoumarin) and [ZnL2Cl2] (2) (L2=3-(4-(2,2′:6′,2″-tripyridyl)-4′-phenylimine)-7-diethylaminocoumarin), were obtained by the solvothermal method from ZnCl2 and coumarin-based terpyridine ligands. The complexes were characterized by spectroscopic methods and single-crystal X-ray diffraction. The Zn2+ in the complexes is coordinated by three nitrogen atoms of the terpyridine ligand and two chloride anions, forming a distorted trigonal bipyramidal environment. Moreover, the UV–Vis absorption and emission spectra of the ligands and complexes in diluted dichloromethane solutions were measured.


2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
H. D. Juneja ◽  
Manisha Joshi ◽  
J. P. Kanfade

The oxaloyl carboxymethyl cellulose (OCMC) complexes of Mn(II), Co(II), Ni(II), Cu(II), and Zn(II) metal ions have been synthesized and the coordination of OCMC in these complexes has been investigated through IR spectra, reflectance spectra, and thermal analysis. On the basis of spectral and thermal data an octahedral geometry was assigned to[Mn(II)OCMC(H2O)2]nand[Co(II)OCMC(H2O)2]n, square planar geometry was assigned to[Cu(II)OCMC]n, and tetrahedral geometry was assigned to[Ni(II)OCMC]nand[Zn(II)OCMC]nMetallic Gel complexes.


2003 ◽  
Vol 81 (11) ◽  
pp. 1398-1405 ◽  
Author(s):  
Hu Cai ◽  
Xianghua Yu ◽  
Tianniu Chen ◽  
Xue-Tai Chen ◽  
Xiao-Zeng You ◽  
...  

A new mixed-amido complex (Me2N)3Ta(Cl)[N(SiMe3)2] (1) was prepared from the reaction of (Me2N)3TaCl2 with 1 equiv. of LiN(SiMe3)2. The reactions of 1 with 1 equiv. of LiN(SiMe3)2 or (Me2N)3TaCl2 with 2 equiv. of LiN(SiMe3)2 gave (Me2N)3[Formula: see text] (2) with a four-membered metallaheterocyclic ring through γ-hydrogen abstraction. In the solid state, 1 adopts a distorted trigonal bipyramidal geometry with the -N(SiMe3)2 and -Cl ligands in the equatorial and axial positions, respectively. The X-ray structure of 2 reveals that it is in a distorted trigonal bipyramidal geometry with a planar metallaheterocyclic ring.Key words: tantalum, γ-hydrogen abstraction, C-H activation, amido complexes, metallacycle.


2007 ◽  
Vol 72 (5-6) ◽  
pp. 649-665 ◽  
Author(s):  
M. Fernanda N. N. Carvalho ◽  
Ana S. D. Ferreira ◽  
João L. Ferreira da Silva ◽  
Luís F. Veiros

3-Hydrazonocamphor, 3-(RR1NN)C10H14O (R = Me, R1 = H), undergoes intramolecular hydrogen bridging by coordination to platinum or palladium. This effect is evidenced by considerable decrease in the ν(C=O) frequency (compared to the free ligand) in the IR spectra of the complexes [MCl2L2] (M = Pd, Pt; L = 3-(RR1NN)C10H14O) as well as by the magnetic non- equivalence of the two ligands, as revealed by 13C NMR. DFT calculations indicate that coordination of 3-(Me(H)NN)C10H14O promotes E/Z isomerization of the hydrazono group of the ligand, inducing formation of intramolecular hydrogen bonding and corresponding stabilization of the complex. Characterization of the complexes [MCl2L2] (M = Pt; L: R, R1 = Me (1), R = Me, R1 = H (2) and M = Pd; L: R = Me, R1 = H (3)) was performed by analytical and spectroscopic techniques. Redox properties of the 3-hydazonocamphors and their complexes were studied by cyclic voltammetry. The structure of trans-[PtCl2{3-(Me2NN)C10H14O}2] was determined by single-crystal X-ray diffraction analysis. The complex has square-planar geometry and crystallizes in the tetragonal P43 space group.


1996 ◽  
Vol 51 (10) ◽  
pp. 1494-1500 ◽  
Author(s):  
Vasily A . Pinchuk ◽  
Ion Neda ◽  
Christian Müller ◽  
Holger Thönnessen ◽  
Peter G. Jones ◽  
...  

The reaction of 1,5-bis(trimethylsilyl)-1,3.5-trimethylbiuret (1) with p-tolylsulfenyl chloride (2) furnished l-(p-tolylthio)-5-trimethylsilyl-1,3,5-trimethylbiuret (3). In the reaction of 3 with phenyldichlorophosphine, 2-phenyl-2-(p-tolylthio)-1,3,5-trimethyl-1,3,5-triaza-4,6-dione- 2-phosphorinonium chloride (4) was formed. The same product was obtained from the reaction of 2-phenyl-1,3,5-trimethyl-1,3,5-triaza-2λ3- phosphorin-4,6-dione (6) with p-tolylsulfenyl chloride (2). Compound 4 was isolated and characterized in the form of the hexachloroantimonate (4a). The spirophosphorane 2-phenyl-1,3,5-trimethyl-1,3,5-triaza-7,10-dioxa-8,9- perchlorobenzo-2λ5-phosphaspiro-[4.5]decan-4,6-dione (7) was prepared by the reaction of 4 with tetrachloroorthobenzoquinone. The new products were characterized by 1H - and 13C NMR spectroscopy, elemental analysis, 31P NMR spectroscopy in the case of 4a. 6 and 7, and mass spectrometry (4a). Single-crystal X-ray structural analyses of compounds 4a and 7 were conducted. The phosphorus atom of 4a has the expected tetrahedral geometry, with a rather short P-S bond of 204.9(2) pm. In 7 the geometry at phosphorus is almost ideal trigonal bipyramidal. Weak hydrogen bonds are formed from a C (:O) group to deuterochloroform of solvation.


2020 ◽  
Vol 76 (10) ◽  
pp. 1562-1565
Author(s):  
Jackson S. McCarthy ◽  
Colin D. McMillen ◽  
Jared A. Pienkos ◽  
Paul S. Wagenknecht

Bis[η5-(tert-butoxycarbonyl)cyclopentadienyl]dichloridotitanium(IV), [Ti(C10H13O2)2Cl2], was synthesized from LiCpCOOt-Bu using TiCl4, and was characterized by single-crystal X-ray diffraction and 1H NMR spectroscopy. The distorted tetrahedral geometry about the central titanium atom is relatively unchanged compared to Cp2TiCl2. The complex exhibits elongation of the titanium–cyclopentadienyl centroid distances [2.074 (3) and 2.070 (3) Å] and a contraction of the titanium–chlorine bond lengths [2.3222 (10) Å and 2.3423 (10) Å] relative to Cp2TiCl2. The dihedral angle formed by the planes of the Cp rings [52.56 (13)°] is smaller than seen in Cp2TiCl2. Both ester groups extend from the same side of the Cp rings, and occur on the same side of the complex as the chlorido ligands. The complex may serve as a convenient synthon for titanocene complexes with carboxylate anchoring groups for binding to metal oxide substrates.


2021 ◽  
Author(s):  
Aman U. Khan

Tetraorganotin compounds [2-(MeOCH2)C6H4]SnR3 (R = Me, n-Bu, Ph) containing a C,O-chelating ligand were prepared in good yield from the reaction of the R3SnCl and [2-(MeOCH2)C6H4]Li. Tethered organotin compounds Ph3Sn(CH2)3OC6H4R (R = Ph, H, CF3, OCH3) were prepared in good yield from the hydrostannylation reactions of the corresponding vinyl ethers with Ph3SnH. Conversion of two organotin compounds to triorganotin chlorides and diorganotin chlorides, (Ph3-nClnSn(CH2)3OC6H4R; R = H, Ph: n = 1, 2), was successfully carried out and characterisation afforded by NMR spectroscopy. X-ray crystallographic studies revealed a tetrahedral geometry for the tetraorganotin Ph3Sn(CH2)3OC6H4CF3, while five-coordinate trigonal bipyramidal structures with relatively short Sn-O (2.7-2.8 Å) interactions were observed for both mono- (Ph2ClSn(CH2)3OC6H4R; R = H, Ph) and dichloride (PhCl2Sn(CH2)3OC6H4R; R = H, Ph) species. Penta-coordinate diorganotin dichlorides containing a C,N- chelating ligand[2-(Me2NCH2)C6H4]RSnCl2 (R = Me, n-Bu, Ph) or C,O- chelating ligand [2-(MeOCH2)C6H4]RSnCl2 (R = Me, n-Bu, Ph) were prepared by treating RSnCl3 with the lithiated salts [2-(Me2NCH2)C6H4]Li and [2-(MeOCH2)C6H4]Li respectively. Organotin chlorides were successfully reduced with LiAlH4 or NaBH4 to produce novel hydrides. Catalytic dehydrocoupling of diorganotin dihydrides to yield polystannanes was explored using a variety of dehydrocoupling catalysts such as Wilkinson’s catalyst, Cp2ZrMe2 or TMEDA. In almost every instance this resulted in the formation of yellow coloured gummy polymeric materials of moderate molecular weights (Mw = 1 × 104 - 1 × 105 Da) and PDI’s (1.3-2.0). The stability of polystannanes containing tethered O or C,N- or C,O-chelating ligands was investigated in both solid and in solution using NMR and UV-Vis spectroscopies. These studies revealed an enhanced stability to ambient light in the solid state and in solution in the dark when compared to known poly(dialkyl)stannanes.


2020 ◽  
Vol 11 (4) ◽  
pp. 319-323
Author(s):  
Cemal Koray Ozer ◽  
Gun Binzet ◽  
Hakan Arslan

Herein, we describe the synthesis and characterization of bis(N-(diethylcarbamothioyl)cyclohexane carboxamido)copper(II) complex, cis-[Cu(L-κ2S,O)2], has been prepared by the reaction of N-(diethyl carbamothioyl)cyclohexanecarboxamide ligand with copper(II) acetate. The green colored crystals of the complex were obtained by slow evaporation of their dichloromethane:ethanol solution (2:1, v:v). The crystal structure of cis-[Cu(L-κ2S,O)2] was obtained by single-crystal X-ray diffraction. The crystal structure reveals an monoclinic C2 (no. 5) space group with cell parameters a = 14.848(3) Å, b = 10.543(2) Å, c = 10.511(2) Å, β = 123.84(3)°, V = 1366.7(7) Å3, Z = 2, T = 153(2) K, μ(MoKα) = 0.979 mm-1, Dcalc = 1.327 g/cm3, 4979 reflections measured (6.6° ≤ 2Θ ≤ 50.68°), 2243 unique (Rint = 0.0223, Rsigma = 0.0444) which were used in all calculations. The final R1 was 0.0225 (>2sigma(I)) and wR2 was 0.0490 (all data). The angular structural index parameter, τ4, is equal to 0.40, which confirms the distorted square planar geometry for the title compound. The puckering parameters (q2 = 0.015(3) Å, q3 = 0.576(3) Å, QT = 0.577(3) Å, θ = 1.6(3)° and φ = 20(11)°) of the title complex show that the cyclohexane ring adopts a chair conformation. The two ethyl groups of the diethyl amine group have anti-orientation with respect to one another. The crystal packing shows the molecules stacked in parallel sheets along [010], accompanied by C3-H3A···O1ⁱ (i -x, +y, 1-z) intermolecular contact.


2021 ◽  
Author(s):  
Aman U. Khan

Tetraorganotin compounds [2-(MeOCH2)C6H4]SnR3 (R = Me, n-Bu, Ph) containing a C,O-chelating ligand were prepared in good yield from the reaction of the R3SnCl and [2-(MeOCH2)C6H4]Li. Tethered organotin compounds Ph3Sn(CH2)3OC6H4R (R = Ph, H, CF3, OCH3) were prepared in good yield from the hydrostannylation reactions of the corresponding vinyl ethers with Ph3SnH. Conversion of two organotin compounds to triorganotin chlorides and diorganotin chlorides, (Ph3-nClnSn(CH2)3OC6H4R; R = H, Ph: n = 1, 2), was successfully carried out and characterisation afforded by NMR spectroscopy. X-ray crystallographic studies revealed a tetrahedral geometry for the tetraorganotin Ph3Sn(CH2)3OC6H4CF3, while five-coordinate trigonal bipyramidal structures with relatively short Sn-O (2.7-2.8 Å) interactions were observed for both mono- (Ph2ClSn(CH2)3OC6H4R; R = H, Ph) and dichloride (PhCl2Sn(CH2)3OC6H4R; R = H, Ph) species. Penta-coordinate diorganotin dichlorides containing a C,N- chelating ligand[2-(Me2NCH2)C6H4]RSnCl2 (R = Me, n-Bu, Ph) or C,O- chelating ligand [2-(MeOCH2)C6H4]RSnCl2 (R = Me, n-Bu, Ph) were prepared by treating RSnCl3 with the lithiated salts [2-(Me2NCH2)C6H4]Li and [2-(MeOCH2)C6H4]Li respectively. Organotin chlorides were successfully reduced with LiAlH4 or NaBH4 to produce novel hydrides. Catalytic dehydrocoupling of diorganotin dihydrides to yield polystannanes was explored using a variety of dehydrocoupling catalysts such as Wilkinson’s catalyst, Cp2ZrMe2 or TMEDA. In almost every instance this resulted in the formation of yellow coloured gummy polymeric materials of moderate molecular weights (Mw = 1 × 104 - 1 × 105 Da) and PDI’s (1.3-2.0). The stability of polystannanes containing tethered O or C,N- or C,O-chelating ligands was investigated in both solid and in solution using NMR and UV-Vis spectroscopies. These studies revealed an enhanced stability to ambient light in the solid state and in solution in the dark when compared to known poly(dialkyl)stannanes.


Sign in / Sign up

Export Citation Format

Share Document