Khalifa Malik - Academia.edu (original) (raw)
Papers by Khalifa Malik
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Journal of Chemical Crystallography, 1999
Complexes [Co(tren)(Tsal)]ClO4·H2O 1 and [Ni(pn)(py)2(NCS)2] 2, (tren = tris(2-aminoethyl)amine, ... more Complexes [Co(tren)(Tsal)]ClO4·H2O 1 and [Ni(pn)(py)2(NCS)2] 2, (tren = tris(2-aminoethyl)amine, Tsal = thiosalicylate ion, pn = 1, 2-diamino propane and py = pyridine) have been synthesized and structurally characterized. Both complexes crystallize in the monoclinic space group C2/c with a = 21.3340(6), b = 11.7754(2), c = 14.8076(5) Å, β = 100.3831(10)°, Z = 8 (1), and a = 7.2573(8), b = 17.8810(11), c = 15.2681(12) Å, β = 101.170(2)°, Z = 4 (2). The metal atoms in both cases have distorted octahedral geometry. In 1, the tren ligand is quadridentate and Tsal is bidentate chelate. In 2, the pn ligand forms a bidentate chelate with the NCS ligands in trans positions. Complex 1 is diamagnetic whereas 2 shows paramagnetism with a magnetic moment of 3.10 B. M.
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Journal of Chemical Crystallography, 2001
The synthesis, properties, and X-ray crystal structure of a Ni(II) complex of the tridentate Schi... more The synthesis, properties, and X-ray crystal structure of a Ni(II) complex of the tridentate Schiff base ligand Me2NCH2CH2CH2N=CHC6H4OH(LH) are described. The complex crystallizes in the monoclinic space group P21/c, with a = 10.180(2), b = 15.169(3), c = 15.293(4) Å, β = 106.69(2)°, and Z = 4. The Ni atom shows a distorted fac-octahedral geometry, with the two Ni—N(Me2) bonds being significantly longer than the two Ni—N(imino) bonds, 2.284(9), 2.310(9) vs. 2.051(2), 2.055(2) Å.
Journal of Chemical Crystallography, 1998
The compound [Cu(phen)(O2CCF3)2]n (phen = 1,10-phenanthroline) has been synthesized and its cryst... more The compound [Cu(phen)(O2CCF3)2]n (phen = 1,10-phenanthroline) has been synthesized and its crystal structure determined. It crystallizes in monoclinic space group C2/c, with a = 19.229(7), b = 11.281(5), c = 7.621(2) Å, β = 104.305(12)°, and Z = 4. The crystal structure is polymeric, being built from infinite zigzag chains of trifluoroacetate bridged copper(II), with the phenanthroline ligands being stacked between the chains. The variable-temperature (13–300 K) magnetic susceptibility and ESR data are reported and a weak ferromagnetic exchange interaction is observed with the exchange parameter estimated as J = 2.9 cm−1.
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Journal of Chemical Crystallography, 1999
The dimeric complex [Mn2(μ-pyS)2(CO)6] (1) reacted with 2 M equivalents of both PPh3 and PHPh2 to... more The dimeric complex [Mn2(μ-pyS)2(CO)6] (1) reacted with 2 M equivalents of both PPh3 and PHPh2 to give the respective monomeric phosphine complexes [Mn(pyS)(L)(CO)3][L = PPh3 (2) and PHPh2 (3)]; with 4 M equivalents of dppm, it yielded the complex [Mn(pyS)(η1-dppm)2(CO)2](4). An X-ray structure determination of 4 shows that it crystallizes in the monoclinic space group P21/n with a = 11.027(3), b = 24.984(7), c = 18.379(5) Å, β = 99.870(8)°, V = 4988(2) Å3, and Z = 4. The complex has an octahedral geometry with the chelating pyS ligand and two CO groups occupying the equatorial sites and the two monodentate dppm ligands lying in the trans positions.
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Journal of Chemical Crystallography, 2001
Treatment of [Ru3(CO)10(μ-dppm)] (1) with the ditelluride Te2(C6H4OEt-4)2 in refluxing toluene af... more Treatment of [Ru3(CO)10(μ-dppm)] (1) with the ditelluride Te2(C6H4OEt-4)2 in refluxing toluene afforded the new aryltellurol bridged complex [Ru2(CO)4(μ-TeC6H4OEt-4)2 (μ-dppm)] (2) together with three known complexes [Ru4(CO)8(μ-CO)(μ4-Te)2(μ-dppm)] (3), [Ru2(CO)6{μ-CH2PPh(C6H4)PPh}] (4), and [Ru2(CO)6{μ-C6H4PPh(CH2)PPh}] (5). All the four complexes were characterized by spectroscopic methods, including an X-ray structure determination for 5. Complex 5 crystallizes in the monoclinic space group P21/c with a = 13.650(2), b = 9.995(2), c = 18.929(3) Å, β = 97.49(2)°, V = 2560.4(8) Å3, and Z = 4. In this complex the two ruthenium atoms are bridged by the phosphino-phosphide ligand C6H4PPh(CH2)PPh which is attached to one Ru by the C6H4 group and a P atom while to the other Ru by both the two P atoms. Both the ruthenium atoms show distorted octahedral geometry. The Ru—Ru bond length is 2.8719(7) Å.
![Research paper thumbnail of Reactions of [Mn 2 (μ-pyS) 2 (CO) 6 ] with bidentate N-donor ligands: Crystal structure of [Mn(η 1 -pyS)(bipy)(CO) 3 ] (bipy = 2,2′-bipyridyl, pySH = pyridine-2-thiol](https://a.academia-assets.com/images/blank-paper.jpg)
](Journal of Chemical Crystallography, 2003
The dimeric complex [Mn2(μ-pyS)2(CO)6] (1) reacted with 2 equivalents of 2,2′-bipyridyl (bipy), 1... more The dimeric complex [Mn2(μ-pyS)2(CO)6] (1) reacted with 2 equivalents of 2,2′-bipyridyl (bipy), 1,10-phenanthroline (phen), and ethylenediamine (en) to give the corresponding monomeric complexes [Mn(η1-pyS)(bipy)(CO)3] (2), [Mn(η1-pyS)(phen)(CO)3] (3), and [Mn(η 1-pyS)(en)(CO)3] (4). The pyS ligand in these complexes acts as a monodentate, two-electron donor ligand, which coordinates to manganese through the sulfur atom. This is confirmed by an X-ray structure determination of 2, which contains two structural isomers in the asymmetric unit. Crystals of this compound are the monoclinic, space group P2 1/c, a = 21.593(4), b = 10.463(2), c = 16.385(3) Å, β = 102.468(13)°, V = 3614.5(12) Å3, and Z = 8. The three CO groups are facially distributed in both isomers, but the relative positions of the pyS and bipy ligands are different.
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Journal of Chemical Crystallography, 1999
Complexes [Co(tren)(Tsal)]ClO4·H2O 1 and [Ni(pn)(py)2(NCS)2] 2, (tren = tris(2-aminoethyl)amine, ... more Complexes [Co(tren)(Tsal)]ClO4·H2O 1 and [Ni(pn)(py)2(NCS)2] 2, (tren = tris(2-aminoethyl)amine, Tsal = thiosalicylate ion, pn = 1, 2-diamino propane and py = pyridine) have been synthesized and structurally characterized. Both complexes crystallize in the monoclinic space group C2/c with a = 21.3340(6), b = 11.7754(2), c = 14.8076(5) Å, β = 100.3831(10)°, Z = 8 (1), and a = 7.2573(8), b = 17.8810(11), c = 15.2681(12) Å, β = 101.170(2)°, Z = 4 (2). The metal atoms in both cases have distorted octahedral geometry. In 1, the tren ligand is quadridentate and Tsal is bidentate chelate. In 2, the pn ligand forms a bidentate chelate with the NCS ligands in trans positions. Complex 1 is diamagnetic whereas 2 shows paramagnetism with a magnetic moment of 3.10 B. M.
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Journal of Chemical Crystallography, 2001
The synthesis, properties, and X-ray crystal structure of a Ni(II) complex of the tridentate Schi... more The synthesis, properties, and X-ray crystal structure of a Ni(II) complex of the tridentate Schiff base ligand Me2NCH2CH2CH2N=CHC6H4OH(LH) are described. The complex crystallizes in the monoclinic space group P21/c, with a = 10.180(2), b = 15.169(3), c = 15.293(4) Å, β = 106.69(2)°, and Z = 4. The Ni atom shows a distorted fac-octahedral geometry, with the two Ni—N(Me2) bonds being significantly longer than the two Ni—N(imino) bonds, 2.284(9), 2.310(9) vs. 2.051(2), 2.055(2) Å.
Journal of Chemical Crystallography, 1998
The compound [Cu(phen)(O2CCF3)2]n (phen = 1,10-phenanthroline) has been synthesized and its cryst... more The compound [Cu(phen)(O2CCF3)2]n (phen = 1,10-phenanthroline) has been synthesized and its crystal structure determined. It crystallizes in monoclinic space group C2/c, with a = 19.229(7), b = 11.281(5), c = 7.621(2) Å, β = 104.305(12)°, and Z = 4. The crystal structure is polymeric, being built from infinite zigzag chains of trifluoroacetate bridged copper(II), with the phenanthroline ligands being stacked between the chains. The variable-temperature (13–300 K) magnetic susceptibility and ESR data are reported and a weak ferromagnetic exchange interaction is observed with the exchange parameter estimated as J = 2.9 cm−1.
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Journal of Chemical Crystallography, 1999
The dimeric complex [Mn2(μ-pyS)2(CO)6] (1) reacted with 2 M equivalents of both PPh3 and PHPh2 to... more The dimeric complex [Mn2(μ-pyS)2(CO)6] (1) reacted with 2 M equivalents of both PPh3 and PHPh2 to give the respective monomeric phosphine complexes [Mn(pyS)(L)(CO)3][L = PPh3 (2) and PHPh2 (3)]; with 4 M equivalents of dppm, it yielded the complex [Mn(pyS)(η1-dppm)2(CO)2](4). An X-ray structure determination of 4 shows that it crystallizes in the monoclinic space group P21/n with a = 11.027(3), b = 24.984(7), c = 18.379(5) Å, β = 99.870(8)°, V = 4988(2) Å3, and Z = 4. The complex has an octahedral geometry with the chelating pyS ligand and two CO groups occupying the equatorial sites and the two monodentate dppm ligands lying in the trans positions.
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Journal of Chemical Crystallography, 2001
Treatment of [Ru3(CO)10(μ-dppm)] (1) with the ditelluride Te2(C6H4OEt-4)2 in refluxing toluene af... more Treatment of [Ru3(CO)10(μ-dppm)] (1) with the ditelluride Te2(C6H4OEt-4)2 in refluxing toluene afforded the new aryltellurol bridged complex [Ru2(CO)4(μ-TeC6H4OEt-4)2 (μ-dppm)] (2) together with three known complexes [Ru4(CO)8(μ-CO)(μ4-Te)2(μ-dppm)] (3), [Ru2(CO)6{μ-CH2PPh(C6H4)PPh}] (4), and [Ru2(CO)6{μ-C6H4PPh(CH2)PPh}] (5). All the four complexes were characterized by spectroscopic methods, including an X-ray structure determination for 5. Complex 5 crystallizes in the monoclinic space group P21/c with a = 13.650(2), b = 9.995(2), c = 18.929(3) Å, β = 97.49(2)°, V = 2560.4(8) Å3, and Z = 4. In this complex the two ruthenium atoms are bridged by the phosphino-phosphide ligand C6H4PPh(CH2)PPh which is attached to one Ru by the C6H4 group and a P atom while to the other Ru by both the two P atoms. Both the ruthenium atoms show distorted octahedral geometry. The Ru—Ru bond length is 2.8719(7) Å.
Journal of Chemical Crystallography, 2003
The dimeric complex [Mn2(μ-pyS)2(CO)6] (1) reacted with 2 equivalents of 2,2′-bipyridyl (bipy), 1... more The dimeric complex [Mn2(μ-pyS)2(CO)6] (1) reacted with 2 equivalents of 2,2′-bipyridyl (bipy), 1,10-phenanthroline (phen), and ethylenediamine (en) to give the corresponding monomeric complexes [Mn(η1-pyS)(bipy)(CO)3] (2), [Mn(η1-pyS)(phen)(CO)3] (3), and [Mn(η 1-pyS)(en)(CO)3] (4). The pyS ligand in these complexes acts as a monodentate, two-electron donor ligand, which coordinates to manganese through the sulfur atom. This is confirmed by an X-ray structure determination of 2, which contains two structural isomers in the asymmetric unit. Crystals of this compound are the monoclinic, space group P2 1/c, a = 21.593(4), b = 10.463(2), c = 16.385(3) Å, β = 102.468(13)°, V = 3614.5(12) Å3, and Z = 8. The three CO groups are facially distributed in both isomers, but the relative positions of the pyS and bipy ligands are different.