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1. Syntheses, crystal structures, DFT calculation and solid-state spectroscopic properties of new zincate(II) complexes with N-(4-substituted phenyl)-N'-(4-nitrophenyl)-oxamate

Author

Zakariyya Ishtaiwi, Deeb Taher, Marcus Korb, Wissam Helal, Afnan Al-Hunaiti, Hassan K. Juwhari, Hazem Amarne, Mohammad W. Amer, Yaser A. YouSef, Sami Klaib, and Sultan T Abu-Orabi

Subjects
Zinc, Oxamide, Solid State Structure, Electrochemistry, Optical Analyses, DFT calculations, Chemistry, QD1-999
Abstract

The electronic effects electron donating and withdrawing groups R on the properties of N-(4-R-phenyl)-N'-(4-nitrophenyl)oxamito zincate(II) complexes was investigated featuring R = Me (a), H (b), F (c), Cl (d) and Br (e). The N-(4-R-phenyl)-N'-(4-nitrophenyl)oxamide ligands 2 were synthesized by reacting ethyl 4-nitrooxanilate with the respective 4-substituted anilines. Subsequent treatment with [nBu4N]OH and [Zn(OAc)2(H2O)2] gave the respective zincate complexes [nBu4N]2[Zn(N-(4-nitrophenyl)-N'-(4-substituted phenyl)oxamides)2] (3). Spectroscopic methods were used to describe compounds 2a–e and 3a–e. Single crystal X-ray diffraction analysis confirmed the formation of 3a–c in the solid state. The tetrahedral coordination sphere of the zinc (II) ion features four amide nitrogen donor atoms based on two ethanediamide ligands. The UV–Vis spectra of Complexes 3a–e display a characteristic LLCT (π → π *) band, which was confirmed by TD-DFT calculations. DFT calculations show that the Zn(II) orbitals do not contribute to the HOMO or LUMO, with the latter being primarily found on the two 4-nitrophenyl rings for compounds 3a − e, while the HOMO-1 and HOMO are located on the 4-substituted phenyl rings. Notably, HOMO and LUMO energies and gabs do not differ significantly. Transitions from HOMO to LUMO + 1 are the most important for all ligands. The luminescence properties of solid compounds 3a − e were also investigated at 298 K. Solid state photoluminescence studies reveal that these complexes emit strong yellow-orange luminescence at 450–600 nm with a maximum at about ∼ 500 nm in the cyan region. Furthermore, the thermal stabilities of compounds 3a − e have been investigated.

Published
2022
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3. Synthesis of di-, tri- and tetranuclear platinum(II) and copper(I) acetylide complexes

Author

Petra Zoufalá, Amaya del Villar, Heinrich Lang, Gerd Rheinwald, and Sami Klaib

Subjects
chemistry.chemical_classification, Stereochemistry, Organic Chemistry, Center (category theory), Alkyne, chemistry.chemical_element, Triple bond, Biochemistry, Copper, Inorganic Chemistry, Crystallography, chemistry.chemical_compound, chemistry, Copper(I) acetylide, Materials Chemistry, Moiety, Molecule, Physical and Theoretical Chemistry, Platinum
Abstract

Heterobimetallic {cis-[Pt](μ-σ,π-C CPh)2}[Cu(N CMe)]BF4 (3a: [Pt] = (bipy)Pt, bipy = 2,2′-bipyridine; 3b: [Pt] = (bipy′)Pt, bipy′ = 4,4′-dimethyl-2,2′-bipyridine) is accessible by the reaction of cis-[Pt](C CPh)2 (1a: [Pt] = (bipy)Pt, 1b: [Pt] = (bipy′)Pt]) with [Cu(N CMe)4]BF4 (2). Substitution of N CMe by PPh3 (4) can be realized by the reaction of 3a with 4, whereby [{cis-[Pt](μ-σ,π-C CPh)2}Cu(PPh3)]BF4 (5) is formed. On prolonged stirring of 3 and 5, respectively, N CMe and PPh3 are eliminated and tetrametallic {[{cis-[Pt](η2-C CPh)2}Cu]2}(BF4)2 (6) is produced. Addition of an excess of N CMe to 6 gives heterobimetallic 3a. When instead of N CMe or PPh3 chelating molecules such as bipy (7) are reacted with 3a then the heterobimetallic π-tweezer molecule [{cis-[Pt](μ-σ,π-C CPh)2}Cu(bipy)]BF4 (8) is formed. Treatment of 8 with another equivalent of 7 produced [Cu(bipy2)]BF4 (9) along with [Pt](C CPh)2. However, when 3b is reacted with 1b in a 1:1 molar ratio then 10 and 11 of general composition [{[Pt](C CPh)2}2Cu]BF4 are formed. These species are isomers and only differ in the binding of the PhC C units to copper(I). A possible mechanism for the formation of 10 and 11 is presented. The solid state structures of 6, 10 and 11 are reported. In 11 the [{cis-[Pt](μ-σ,π-C CPh)2}2Cu]+ building block is set-up by two nearly orthogonal positioned bis(alkynyl) platinum units which are connected by a Cu(I) ion, whereby the four carbon–carbon triple bonds are unsymmetrical coordinated to Cu(I). In trimetallic 10 two cis-[Pt](C CPh)2 units are bridged by a copper(I) center, however, only one of the two PhC C ligands of individual cis-[Pt](C CPh)2 fragments is η2-coordinated to Cu(I) giving rise to the formation of a [(η2-C CPh)2Cu]+ moiety with a linear alkyne–copper–alkyne arrangement (alkyne = midpoint of the C C triple bond). In 6 two almost parallel oriented [Pt](C CPh)2 planes are linked by two copper(I) ions, whereby two individual PhC C units, one associated with each Pt building block, are symmetrically π-coordinated to Cu.

Published
2007

4. Trimethylsilyl-functionalised bis(indenyl)iron(II) complexes: solid-state structure of [η5-1,3-(SiMe3)2C9H5]2Fe

Author

Heinrich Lang, Sami Klaib, Glen M. Fern, and Owen J. Curnow

Subjects
Steric effects, Trimethylsilyl, Organic Chemistry, chemistry.chemical_element, Biochemistry, Solid state structure, Chloride, Ferrous, Inorganic Chemistry, Crystallography, chemistry.chemical_compound, chemistry, Molar ratio, Materials Chemistry, medicine, Lithium, Physical and Theoretical Chemistry, medicine.drug
Abstract

The synthesis of the bis(η5-indenyl)iron sandwich complexes (η5-1-SiMe3–C9H6)2Fe (3a), (η5-2-SiMe3–C9H6)2Fe (3b), [η5-1,2-(SiMe3)2C9H5]2Fe (4a) and [η5-1,3-(SiMe3)2C9H5]2Fe (4b), by the reaction of the appropriate lithium indenide salts [prepared from 1-SiMe3–C9H7 (2a), 2-SiMe3–C9H7 (2b), 1,2-(SiMe3)2C9H6 (2c) or 1,3-(SiMe3)2C9H6 (2d)] with ferrous chloride (1) in a 2:1 molar ratio is discussed. The solid-state structure of 4b was determined by single-crystal X-ray diffractometry. Complex 4b exists in a gauche conformation, showing that the indenyl ligands are sterically imposed by the bulk of the Me3Si substituents. The average Fe–C distance is 2.091(3) A. Cyclovoltammetric studies indicate that 3 and 4 are redox-active with one-electron oxidations [E1/2=−270 to −360 mV versus Fc/Fc+, Fc=(η5-C5H5)2Fe].

Published
2004

5. Porphyrins with a carbosilane dendrimer periphery as synthetic components for supramolecular self-assembly

Author

Roy Buschbeck, Tobias Rüffer, Sami Klaib, Heinrich Lang, Bernhard Walfort, and Zakariyya Ishtaiwi

Subjects
Supramolecular chemistry, Ring (chemistry), Photochemistry, Porphyrin, Porphyrine, Carbosilan-Dendrimere, Supramolekulare Erkennung, Porphyrins, Carbosilane Dendrimers, supramolecular Self-assembly, Inorganic Chemistry, chemistry.chemical_compound, Crystallography, chemistry, Phenylene, Porphyrine, Dendrimer, Molecule, Self-assembly, ddc:546, Pyrrole
Abstract

The preparation of the shape-persistent carbosilane-functionalized porphyrins H2TPP(4-SiRR’Me)4, Zn(II)- TPP(4-SiRR’Me)4 (R = R’ = Me, CH2CHvCH2, CH2 CH2CH2OH; R = Me, R’ = CH2 CHvCH2, CH2CH2CH2OH; TPP = tetraphenyl porphyrin), H2TPP(4-Si(C6H4-1,4-SiRR’Me)3)4, and Zn(II)-TPP(4-Si- (C6H4-1,4-SiRR’Me)3)4 (R = R’ = Me, CH2CHvCH2; R = Me, R’ = CH2CHvCH2) using the Lindsey condensation methodology is described. For a series of five samples their structures in the solid state were determined by single crystal X-ray structure analysis. The appropriate 0th and 1st generation porphyrin-based 1,4-phenylene carbosilanes form 2D and 3D supramolecular network structures, primarily controlled by either π–π interactions (between pyrrole units and neighboring phenylene rings) or directional molecular hydrogen recognition and zinc–oxygen bond formation in the appropriate hydroxyl-functionalized molecules. UV-Vis spectroscopic studies were carried out in order to analyze the effect of the dendritic branches on the optical properties of the porphyrin ring. Dieser Beitrag ist aufgrund einer (DFG-geförderten) Allianz- bzw. Nationallizenz frei zugänglich.

Published
2014

6. Reactions of ring-substituted titanocene dichlorides with thiocyanate ions: Synthesis of new S-bonded thiocyanato titanocene complexes, and crystal structure of (tBu-C5H4)2Ti(NCS)2

Author

Sultan T. Abu-Orabi, Gottfried Huttner, Sami Klaib, Ibrahim Jibril, and L. Zsolnai

Subjects
Thiocyanate, Stereochemistry, Chemistry, Organic Chemistry, Titanocene dichloride, Crystal structure, Biochemistry, Medicinal chemistry, Chloride, Inorganic Chemistry, chemistry.chemical_compound, X-ray crystallography, Materials Chemistry, medicine, Molecule, Ammonium thiocyanate, Physical and Theoretical Chemistry, Metallocene, medicine.drug
Abstract

The asymmetrical titanocene dichloride (1,3- t Bu 2 C 5 H 3 )( t Bu 2 C 5 H 4 )TiCl 2 ( I ) has been prepared from (1,3- t Bu 2 C 5 H 3 )TiCl 3 and ( t BuC 5 H 4 )Li. The reactions of I and of (1,3- t Bu 2 C 5 H 3 ) 2 TiCl 2 with an excess of ammonium thiocyanate afforded the S-bonded thiocyanato complexes (1,3- t Bu 2 C 5 H 3 )( t BuC 5 H 4 )Ti(SCN) 2 ( IV ) and (1,3- t Bu 2 C 5 H 3 ) 2 Ti(SCN) 2 ( V ) respectively. A similar reaction of ( t BuC 5 H 4 ) 2 TiCl 2 with excess anmmonium thiocyanate produced the S-bonded thiocyanato complex ( t Bu C 5 H 4 ) 2 Ti(SCN) 2 ( II ) as a minor product and the N-bonded thiocyanato complex ( t BuC 5 H 4 ) 2 Ti(NCS) 2 ( III ) as the major product. Similar reaction of ( t BuC 5 H 4 ) 2 TiCl 2 with ammonium thiocyanate in 1 : 1 molar ratios gave ( t BuC 5 H 4 ) 2 Ti(Cl)(NCS) ( VI ). Crystal structure of III was determined.

Published
1994

7. Controlled synthesis of (1,3-tBu2-C5H3)2TiCl2 and (1,3-tBu2-C5H 3)TiCl3. Crystal structure and reactions of (1,3-tBu2-C5H3)TiCl3

Author

Sultan T. Abu-Orabi, Sami Klaib, Gottfried Huttner, Ibrahim Jibril, and Wolfgang Imhof

Subjects
chemistry.chemical_classification, Stereochemistry, Carboxylic acid, Organic Chemistry, Crystal structure, Sodium oxalate, Biochemistry, Inorganic Chemistry, chemistry.chemical_compound, chemistry, Polymer chemistry, Materials Chemistry, Methanol, Physical and Theoretical Chemistry
Abstract

The compounds (1,3-tBu2C5H3)2TiCl2 (I) and (1,3-tBu2C5H3)TiCl3 (II) were prepared in good yields from TiCl4 and (1,3-tBu2-C5H3)Li. Reactions of II with methanol, ethane-1,2-diol, sodium oxalate, and 2-pyrazine carboxylic acid afforded various organotitanium complexes. The crystal structure of II was determined.

Published
1992

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