Browsing Chemistry by Author "Gichumbi, Joel M."
Now showing items 1-14 of 14
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Application of arene ruthenium(II) complexes with pyridine-2-carboxaldimine ligands in the transfer hydrogenation of ketones
Gichumbi, Joel M.; Friedrich, Holger B.; Omondi, Bernard (Elsevier, 2016-05)The reaction of various pyridine-2-carboxaldimine ligands with the [(η6-arene)Ru(μ-Cl)Cl]2 dimer followed by a metathesis reaction with ammonium hexaflourophosphate, yielded the ruthenium(II) arene complex salts ... -
Comparison of Chemical and Mineralogical Properties of Geophagic Materials from Taita and Mombasa, Kenya
Gichumbi, Joel M.; Maghanga, Justin Kambale; Ongulu, Roselyn; Cheshari, E.C; Gichuki, J.G. (2012-10)Geophagy is the deliberate consumption of soil and clay deposits by animals including man. The practice is widespread particularly in pregnant women in Africa. This study of geophagic soil from coast province in Kenya had ... -
Crystal structure of chlorido-(η5-pentamethylcyclopenta dienyl)-((bis-pyrazol-1-yl) methane-κ2N, N′) rhodium (III) hexafluorophosphate
Gichumbi, Joel M.; Zamisa, Sizwe J.; Friedrich, Holger B. (2019-11-13)C17H23ClN4RhF6P, monoclinic, P21/c (no. 14), a = 10.6954(2) Å, b = 15.3868(3) Å, c = 12.6130(2) Å, β = 90.5590(10)°, V = 2075.60(7) Å3, Z = 4, Rgt(F) = 0.0296, wRref(F2) = 0.0727, T = 100(2) K. -
Crystal structure of chlorido-(η6 - toluene)(2,2′-bipyridine-κ2 N,N′)ruthenium(II) hexafluorophosphate, C17H16ClN2RuPF6
Gichumbi, Joel M.; Zamisa, Sizwe J.; Friedrich, Holger B. (De Gruyter, 2022)C17H16ClN2RuPF6, monoclinic, P21/c (no. 14), a = 14.4426(9) Å, b = 8.3311(5) Å, c = 16.413(1) Å, β = 109.2690°, V = 1864.2(2) Å3 , Z = 4, Rgt(F) = 0.0309, wRref(F2 ) = 0.0697, T = 173 K. -
Crystal structure of chlorido-(η6-p-cymene)-(N- (2-fluorophenyl)-1-(pyridin-2-yl) methanimine-κ2N, N′) ruthenium (II)–acetone (1/1), C22H23ClN2F7OPRu.
Gichumbi, Joel M.; Omondi, Bernard *; Friedrich, Holger B. (2010-01)C 22 H 23 ClN 2 F 7 OPRu, monoclinic, P 2 1 / c (no. 14), a = 7.30480(10) Å, b = 12.9540(3) Å, c = 28.7076(6) Å, β = 96.6990(10)°, V = 2697.95(9) Å ³ , Z = 4, Rgt ( F ) = 0.0196, wRref ( F² ) = 0.0479, T = 100(2) K. -
Crystal structure of η 6 -p-cymene-iodido-(N-isopropyl-1-(pyridin-2-yl) methanimine-κ 2N,N′)ruthenium(II) hexafluorophosphate(V), C19H26IN2F6Ru
Gichumbi, Joel M.; Omondi, Bernard; Friedrich, Holger B. (De Gruyter, 2019-12-07)C19H26IN2F6Ru, triclinic, P¯1 (no. 2), a = 9.240(2) Å, b = 10.019(3) Å, c = 12.689(3) Å, α = 78.921°, β = 81.596(10)°, γ = 83.654°, V = 1136.30(5) Å3 , Z = 2, Rgt(F) = 0.0174, wRref(F 2 ) = 0.0440, T = 173 K. -
Crystal structure of η6-p-cymene-iodido- (N-isopropyl-1-(pyridin-2-yl) methanimine-κ2N, N′) ruthenium (II) hexafluorophosphate (V), C19H26IN2F6Ru
Gichumbi, Joel M.; Omondi, Bernard; Friedrich, Holger B. (2019-12-07)C19H26IN2F6Ru, triclinic, P1̄ (no. 2), a = 9.240(2) Å, b = 10.019(3) Å, c = 12.689(3) Å, α = 78.921°, β = 81.596(10)°, γ = 83.654°, V = 1136.30(5) Å3, Z = 2, Rgt(F) = 0.0174, wRref(F2) = 0.0440, T = 173 K. -
Effect of Human Activities and Seasonal Variation on Water Quality of Nkenye (Chikuu) Stream in Chuka, Kenya
Ombaka, Ochieng; Gichumbi, Joel M.; Mukono, Simon T.; Kibara, D. (2013-01)Composite water and sediment samples were taken from Nkenye stream at five different sampling stations during wet and dry seasons. Water quality parameters were analyzed using standard methods to ascertain ... -
A study of new half-sandwich Osmium(II) complexes with bidentate N,N-chelating ligands and their use in the transfer hydrogenation of ketones
Gichumbi, Joel M.; Omondi, Bernard; Friedrich, Holger (2016-11)The reaction of appropriate N,N-bidentate ligands with the [(η6-p-cymene)Os(μ-Cl)Cl]2 dimer, followed by metathesis reaction with NH4PF6, gave the new osmium(II) arene complex salts [(η6-p-cymene)OsCl(C5H4N-2-CH=N-R]PF6, ... -
Synthesis and characterization of half-sandwich ruthenium(II) complexes with N-alkyl pyridyl-imine ligands and their application in transfer hydrogenation of ketones
Gichumbi, Joel M.; Friedrich, Holger B.; Omondi, Bernard (2016-08-24)A series of new arene ruthenium(II) complexes were prepared by reaction of ruthenium(II) precursors of the general formula [(η6-arene)Ru(μ-Cl)Cl]2 with N,N′-bidentate pyridyl-imine ligands to form complexes of the type ... -
Synthesis and characterization of piano-stool ruthenium complexes with N,N′-pyridine imine bidentate ligands and their application in styrene oxidation
Gichumbi, Joel M.; Friedrich, Holger B.; Omondi, Bernard (Elsevier, 2016-04)The new complexes [(η6-arene)RuCl(C5H4N-2-CH N-R)]PF6 (arene = C6H6 with R = 4- flourophenyl (1), 4-chlorophenyl (2), 4-bromophenyl (3), 4 -iodophenyl (4), 2, 5-dichlorophenyl (5) or p-cymene with R = 4-flourophenyl (6), ... -
Synthesis and characterization of some new half-sandwich ruthenium(II) complexes with bidentate N,N′-ligands and their application in alcohol oxidation
Gichumbi, Joel M.; Friedrich, Holger B.; Omondi, Bernard (2016)Graphical abstract New ruthenium (II) pyridine-imine complexes have been prepared and characterized. They show good catalytic activity in the oxidation of alcohols to carbonyl products using NaIO4 in a H2O/tert-butanol mixture. -
Synthesis and characterization of water-soluble arene- ruthenium complexes and their application in biphasic olefin oxidation
Gichumbi, Joel M.; Friedrich, Holger B.; Omondi, Bernard (2018-12-25)New water-soluble complexes [(η6-C6H6)RuCl(C5H4N-2-CH = N-R)]Cl (1) (with R = 4-hydroxymethylphenyl (a), 2,4-dichlorophenyl (b), 2-fluorophenyl (c), 3-carboxyphenyl (d)) have been synthesized by reacting [(η6-C6H6)Ru(μ-Cl)Cl]2 ... -
Synthesis, characterization, and antimicrobial studies of half-sandwich η6-toluene ruthenium complexes with N,N′-bidentate ligands
Gichumbi, Joel M.; Friedrich, Holger B.; Omondi, Bernard; Chenia, Hafizah Y. (Taylor and Francis, 2020-07-29)Nine new complexes [(η6-C6H5-CH3)RuLCl]+(PF6)ˉ (where L = N,N′-bidentate ligand; (C5H4NCH = N-Ar) where Ar = 4-methylphenyl (C20H20ClF6N2PRu, 1); 3,4-dimethylphenyl (C21H22ClF6N2PRu, 2); 2,4,6-trimethylphenyl (C21H24ClF6N2PRu, ...