Syntheses, structures, and electrochemical properties of four complexes based on 4-ferrocenylbutyrate ligand

Four ferrocenyl complexes with the formulas {[Mn(η²-OOC(CH₂)₃Fc)₂(bbbm)]·CH₃OH}_n (1), {[Co(OOC(CH₂)₃Fc)(η²-OOC(CH₂)₃Fc)(bbbm)]·CH₃OH}_n (2), {[Ni(OOC(CH₂)₃Fc)₂(bbbm)(CH₃OH)₂]·2CH₃OH}_n (3) and [Pb₆(μ₂-OOC(CH₂)₃Fc)₂(μ₃-OOC(CH₂)₃Fc)₂(μ₂-η²-OOC(CH₂)₃Fc)₂(η²-OOC(CH₂)₃Fc)₂(μ₄-O)₂] (4) (Fc = (η⁵-C₅H₅)Fe(η⁵-C₅H₄), bbbm = 1,1-(1,4-butanediyl)bis-1H-benzimidazole) have been synthesized and characterized by single crystal X-ray diffraction. Owing to the different conformations of the bbbm units in complexes 1 (or 2) and 3, complexes 1 and 2 possess 1D helical chain structure with 2₁ screw axes along the b-direction, while complex 3 shows a 1D linear chain structure with ferrocenylbutyrate groups hanging on the chain. Complex 4 is a hexanuclear complex and exhibits a nano-scale wheel-like framework with six Pb(II) ions as a core and eight 4-ferrocenylbutyrate ligands as branches. The cyclic voltammetric studies show that the formal potentials of the four complexes are close to the free ferrocenylbutyrate ligand, which indicates that the coordination of the metal ions to the ferrocenyl ligand does not have significant effects on the redox potential of the ferrocenylbutyrate ligand. Further investigations suggest that the redox processes of the ferrocenylbutyrate ligand and complexes 1-4 are all chemically quasi-reversible processes and controlled by diffusion.     

Two 1-D metal-organic polymers constructed from bis-benzimidazole-based ligands: syntheses,crystal structures,and luminescent properties

By combination of Mn(II) and Hg(II) salts with a flexible building unit 1,1′-(1, 5-pentanediyl)bis-1H-benzimidazole (pbbm), two 1-D chain metal-organic polymers [Mn(SCN)₂(pbbm)₂] _n (1) and {[HgCl₂(pbbm)] · DMF} _n (2) have been prepared. The polymeric 1-D chains in 1 consist of parallel ribbons of rings, whereas 2 possesses a 1-D zig-zag chain framework based on tetrahedral mercury atoms bridged by pbbm molecules and terminally coordinated by two chlorides. The significant differences of these metal-organic frameworks indicate that the flexible pbbm ligand adjusts its conformation to meet the requirement of the coordination preference of the metal center. The photoluminescent properties of these new materials have been studied in the solid state at room temperature.     

Synthesis, crystal structures and catalytic properties of two 1D cobalt(II) coordination polymers

Two new cobalt(II) coordination polymers, namely [Co_1.5(PhCOO)₃(bbbm)_1.5(H₂O)] _n (1) and [Co(chdc)(bbbm)] _n (2) (bbbm = 1,1′-(1,4-butanediyl)bis-1H-benzimidazole, H₂chdc = 1,4-cyclohexanedicarboxylic acid), have been synthesized and structurally characterized by single crystal X-ray diffraction. The cobalt(II) centers display different environments, with trigonal–bipyramidal and octahedral geometries in 1 and a tetrahedral geometry in 2. The 1D linear chains of complex 1 and ladder-like chains of complex 2 are bridged by bbbm in bis-monodentate coordination mode; the variation of the carboxylate co-ligand effectively tunes the resulting framework architecture. The degradation of methyl orange in a photochemical Fenton-like process using complexes 1 and 2 as catalysts was investigated.     

Five dinuclear iron carbonyl complexes based on substituted tetramethylcyclopentadienyl ligands: synthesis and crystal structures

Thermal treatment of the substituted tetramethylcyclopentadienes [C₅Me₄HR] [R?=?n-propyl (1), i-propyl (2), cyclopentyl (3), cyclohexyl (4), and 4-NMe₂Ph (5)] with Fe(CO)₅ gave five new substituted tetramethylcyclopentadienyl dinuclear iron carbonyl complexes, [η⁵-C₅Me₄CH₂CH₂CH₃]₂Fe₂(CO)₄ (6), [η⁵-C₅Me₄CH(CH₃)₂]₂Fe₂(CO)₄ (7), [η⁵-C₅Me₄CH(CH₂)₄]₂Fe₂(CO)₄ (8), [η⁵-C₅Me₄CH(CH₂)₅]₂Fe₂(CO)₄ (9), and [(η⁵-C₅Me₄)(4-NMe₂Ph)]₂Fe₂(CO)₄ (10). The new complexes were characterized by elemental analysis, IR, and ¹H NMR spectra. The molecular structures of 6, 8, 9, and 10 were determined by X-ray single crystal diffraction.     

Construction of Cd(II)–ferrocenesuccinate coordination complexes via changing adjuvant ligands and anions

Seven Cd(II)–ferrocenesuccinate coordination complexes with the formulas [Cd(η²-FcCOC₂H₄COO)₂(pbbbm)]₂ (1), [Cd(η²-FcCOC₂H₄COO)(pbbbm)Cl]₂ (2), [Cd(η²-FcCOC₂H₄COO)(pbbbm)I]₂ (3), {[Cd(η²-FcCOC₂H₄COO)₂(btx)₂]₂(CH₃OH)_0.5} (4), [Cd(η²-FcCOC₂H₄COO)₂(bix)]₂(H₂O) (5), {[Cd(η²-FcCOC₂H₄COO)(bbbm)_1.5Cl] · (CH₃OH)_0.5}_n (6), and {[Cd(η²-FcCOC₂H₄COO)(mbbbm)Cl] · (H₂O)_2.75}_n (7) [pbbbm = 1,4-Bis(benzimidazole-1-ylmethyl)benzene), btx = 1,4-bis(triazol-1-ylmethyl)benzene), mbbbm = 1,3-bis(benzimidazole-1-ylmethyl)benzene), bix = 1,4-bis(imidazol-1-ylmethyl)benzene, bbbm = 1,1-(1,4-Butanediyl)bis-1H-benzimidazole)] have been synthesized and characterized. Single-crystal X-ray analysis reveals that complexes 1–5 are all dimers and bridged by pbbbm, btx and bix, respectively. But the five complexes present some differences in their dimeric conformations, which can be ascribed to the impacts of adjuvant ligands and counter anions. In contrast to complexes 1–5, both 6 and 7 are of 1-D structures (with the same counter anions), and the former is double ladder-like structure only bridged by bbbm, while the latter is chain-like structure bridged by chlorine anions and adjuvant ligand mbbbm. Notably, various π–π interactions are found in complexes 1–7, and they have significant contributions to molecular self-assembly processes. The electrochemical studies of complexes 1–7 in DMF solution display irreversible redox waves and indicate that the half-wave potentials of the ferrocenyl moieties in these complexes are all shifted to positive potential compared with that of ferrocenesuccinate.     

HgII-containing MOFs constructed from bis-benzimidazole-based ligand with highly selective anion-exchange capacity

Two Hg(II)-containing metal–organic frameworks (MOFs) based on 1,1′-(1,5-pentanediyl)bis-1H-benzimidazole (pbbm), {[HgBr₂(pbbm)]?·?DMF} _n (1) and [HgI₂(pbbm)]₂ (2), have been constructed to explore new and potent ion-exchange materials. Single-crystal X-ray diffraction shows that 1 features a 1-D zigzag chain framework, while 2 presents a dimeric structure in which two Hg(II) cations are bridged by two pbbm ligands. The significant differences of these MOFs indicate that the counteranions have impact on assembling and structures of the resultant MOFs. Remarkably, coordinated Br^? in 1 can be replaced completely when the solid polymer is treated with an aqueous solution containing I^?. Confirmation of retention of structure is provided by FT-IR spectra and the XRPD pattern. The thermal stabilities of 1 and 2 have also been investigated.     

Manganese(II) complexes of hydrazone based NNO-donor ligands and their catalytic activity in the oxidation of olefins

The reaction between tridentate NNO donor hydrazone ligands, (E)-2-cyano-N′-(phenyl(pyridin-2-yl)methylene)acetohydrazide (HL¹) and (E)-2-cyano-N′-(1-(pyridin-2-yl)ethylidene)acetohydrazide (HL²), with MnCl₂·4H₂O in methanol resulted in [Mn(HL¹)Cl₂(CH₃OH)] (1) and [Mn(HL²)Cl₂(CH₃OH)] (2). Molecular structures of the complexes were determined by single-crystal X-ray diffraction. All of the investigated compounds were further characterized by elemental analysis, FT-IR, TGA, and UV–Vis spectroscopy. These complexes were used as catalysts for olefin oxidation in the presence of tert-butylhydroperoxide (TBHP) as an oxidant. Under similar experimental conditions with equal manganese loading, the presence of [Mn(HL²)Cl₂(CH₃OH)] (2) resulted in higher conversion than [Mn(HL¹)Cl₂(CH₃OH)] (1).     

Construction of Zn(II)-ferrocenyl carboxylate coordination complexes via changing adjuvant ligands

Five Zn(II)-ferrocenyl carboxylate complexes, {[Zn(OOCClH₃C₆Fc)(η ²OOCClH₃C₆Fc)(dpa)]?·?(H₂O)} (1), [Zn(η ²-OOCClH₃C₆Fc)₂(2,2′-dip)]?·?(H₂O)_0.25} (2), {[Zn(η-OOCClH₃C₆Fc)₂(bix)]₂?·?(THF)} (3), [Zn(η-OOCClH₃C₆Fc)₂?·?(Hfcz)] _n (4) and {[Zn(η-OOCClH₃C₆Fc)₂(H₂L₁)]?·?(DMF)₂} _n (5) [dpa?=?2,2′-dipyridylamine, 2,2′-dip?=?2,2′-bipyridine, bix?=?1,4-bis(imidazol-1-ylmethyl)benzene, Hfcz?=?α-(2,4-difluorophenyl)-α-(1H-1,2,4-triazol-l-ylmethyl)-1H-1,2,4-triazole-l-ethanol, H₂L₁?=?N,N′-bis(pyridin-4-yl)pyridine-2,6-dicarboxamide, Fc?=?ferrocene, FcC₆H₃ClCOONa?=?sodium 2-chloro-4-ferrocenylbenzoic], have been synthesized and characterized. Single-crystal X-ray analysis reveals that 1 and 2 are mononuclear structures, 3 is a dimer, and 4 and 5 are 1-D structures. The five complexes exhibit some differences in their conformations, which can be attributed to the influence of adjuvant ligands. Notably, various π–π interactions as well as CH/π interactions are discovered in 1–5, and they have significant contributions to self-assembly. The electrochemical properties of 1–5 indicate that half-wave potentials shift to positive potential compared with that of 2-chloro-4-ferrocenylbenzoic acid.     

The synthesis of complexes using precursor complexes with ferrocenyl carboxylate units as building blocks

Using ferrocenyl carboxylates as functional ligands, we synthesized a mononuclear complex [Zn(η²-OOCCHCHFc)₂(CH₃OH)₂] (1) and a binuclear complex [Cd(bafca)₂(H₂O)₂]₂ (2) (bafca⁻ = α-benzamido-β-ferrocenylacrylic carboxylate) as precursor complexes. Investigation on the substitution reaction of precursor complexes as building blocks in solution-state, four complexes [Zn(OOCCHCHFc)₂(bbbm)]_n (1a), {[Zn(OOCCHCHFc)(ntb)](CH₃OH)} (1b), [Cd(bafca)₂(2,2′-bpy)]₂ · 9H₂O (2a) and {[Cd(bafca)₂(bbbm)(CH₃OH)₂] · 6CH₃OH}_n (2b) were obtained (bbbm = 1,1-(1,4-Butanediyl)bis-1H-benzimidazole, ntb = N,N-bis(1H-benzimidazol-2-ylmethyl)-1H-Benzimidazole-2-methanamine and 2,2′-bpy = 2,2′-bipyridine). As anticipated, the structural integrity of precursor complexes can be maintained in these four complexes. It indicates that we can synthesize the desired complexes with the destination structures by using precursor complexes as building blocks and choosing appropriate auxiliary ligands. In addition, the electrochemical properties of all complexes were investigated, and it can be seen from the results that half-wave potentials of these complexes are slightly higher than that of the corresponding ligand.     

Syntheses,spectroscopic and structural studies of indenyl ruthenium complexes incorporating amine and nitrile ligands: molecular structures of [(η5-C9H7) Ru(η2-dppe)(CH3CN)]PF6 and [(η5-C9H7)Ru(η2-dppe)(NH3)]PF6

The reaction of [(η⁵-C₉H₇)Ru(η²-dppe)Cl] (1) with monodentate nitriles, (L) in the presence of NH₄PF₆ afforded the complexes [(η⁵-C₉H₇)Ru(η²-dppe)(L)]PF₆, with L?=?CH₃CN (2a), CH₃CH=CHCN (2b), NCC₆H₄CN (2c), C₆H₅CH₂CN (2d), respectively. However, reaction of 1 with NH₄PF₆ in methanol yielded an amine complex of the type [(η⁵-C₉H₇) Ru(η²-dppe)(NH₃)]PF₆ (3a). The complexes were fully characterized by spectroscopy and analytical data. The molecular structures of the complexes [(η⁵-C₉H₇)Ru(η²-dppe) (CH₃CN)]PF₆ (2a) and [(η⁵-C₉H₇)Ru(η²-dppe)(NH₃)]PF₆ (3a) have been determined by single crystal X-ray analyses.     

Self-assembly of two 1D tube-like metal-organic networks based on flexible bis(benzimidazole) ligand and 5-nitroisophthalate

Two new polymeric networks, [Co(pbbm)(nip)] · H₂O (1) and [Ni(pbbm)(nip) · (H₂O)] (2) (pbbm = 1,1-(1,3-propanediyl)bis-1H-benzimidazole, H₂nip = 5-nitroisophthalic acid) have been hydrothermally synthesized and structurally characterized by single-crystal X-ray diffraction. Complex 1 is an interesting one-dimensional (1D) tube-like chain utilizing [Co₂(pbbm)₂] metallocycle as subunit. Complex 2 is also an interesting 1D tube-like chain based on [Ni₂(pbbm)₂] loop subunit. In the title complexes, the ??-?? stacking and H-bonding interactions extend the 1D tube into 3D supramolecular framework, respectively. The structural differences between the title complexes indicate the importance of metal ions for the creation of molecular architectures. Furthermore, the luminescent properties of 1 and 2 were investigated.     

Synthesis, characterization and reactivity studies of the new compound [Os3(CO)9(μ3-η,η,η-{C5H5FeC5H3CCC(S)C(Fc)CHO}]

Processes such as S-C and C-H bond activations as well as C-C coupling reactions have taken place in the synthesis of the new compound [Os₃(CO)₉(μ₃-η²,η³,η³-{C₅H₅FeC₅H₃CCC(S)C(Fc)CHO}] (Fc = C₅H₄FeC₅H₅), which contains an aldehyde oxametallacycle. A reactivity study of it has been carried out. In addition, other new triosmium clusters such as [Os₃(CO)₉(μ₃,η²-CCFc)(μ,η¹-SCCFc)], [Os₃(CO)₁₀(μ,η²-CCFc)(μ,η¹-SCCFc)] and [Os₃(CO)₉(μ-CO)(μ₃,η²-FcCCSCCFc)] have been prepared from the reaction of [Os₃(CO)₁₀(NCMe)₂] and FcCCSCCFc. All the compounds have been characterized by analytical and spectroscopic techniques. The crystal structures of [Os₃(CO)₉(μ₃,η²-CCFc)(μ,η¹-SCCFc)] and [Os₃(CO)₉(μ₃-η²,η³,η³-{C₅H₅FeC₅H₃CCC(S)C(Fc)CHO}] have been determined by X-ray crystallography and some electrochemical studies have also carried out.     

SYNTHESES AND REACTIONS OF THE COMPLEXES (η5-C5Me5)Re(CO)2(C6CL5–nHn)Cl (n = 2,3): COMPOUNDS DERIVED FROM INITIAL C—CI ACTIVATION

Abstract

The UV irradiation of (η⁵-C₅Me₅)Re(CO)₃ in the presence of 1,2,4,5-C₆Cl₄H₂ and 1,3,5-C₆Cl₃H₃ (λ = 350 nm, hexane solution) effected intramolecular C—Cl activation, generating the complexes trans-(η⁵-C₅Me₅)Re(CO)₂(2,4,5-C₆Cl_5-nH_n)Cl, ((1), n = 2; (2), n = 3), respectively. Complex (1) dissolved in polar organic solvents produces, an equilibrium mixture with its cis isomer. The reaction of (1) with AgBF₄, in acetonitrile, led to formation of the cationic complex [cis-(η⁵-C₅Me₅)Re(CO)₂(2,4,5-C₆Cl₃H₂)(MeCN)]⁺. The tetramethylfulvene complex (η⁶-C₅Me₄CH₂)Re(CO)₂(2,4,5-C₆Cl₃H₂) (3) was obtained by reacting the cationic complex with the fluorinating agent Et₃N′3HF.     

Reactions of Cyclohexyl Isocyanide with η5‐Substituted Cyclo‐pentadienyl MoMo Triply Bonded Complexes. Crystal Structure of [Mo(CO)2(η5‐C5H4CO2CH3)]2(μ‐η2‐CNC6H11)

Reactions of one or two equiv. of cyclohexyl isocyanide in THF at room temperature with Mo?Mo triply bonded complexes [Mo(CO)₂(η⁵‐C₅H₄R)]₂ (R=COCH₃, CO₂CH₃) gave the isocyanide coordinated Mo? Mo singly bonded complexes with functionally substituted cyclopentadienyl ligands, [Mo(CO)₂(η⁵‐C₅H₄R)]₂(μ‐η²‐CNC₆H₁₁) ( 1a , R=COCH₃; 1b , R=CO₂CH₃) and [Mo(CO)₂(η⁵‐C₅H₄R)(CNC₆H₁₁)]₂ ( 2a , R=COCH₃; 2b , R=CO₂CH₃), respectively. Complexes 1a , 1b and 2a , 2b could be more conveniently prepared by thermal decarbonylation of Mo? Mo singly bonded complexes [Mo(CO)₃(η⁵‐C₅H₄R)]₂ (R=COCH₃, CO₂CH₃) in toluene at reflux, followed by treatment of the resulting Mo?Mo triply bonded complexes [Mo(CO)₂(η⁵‐C₅H₄R)]₂ (R=COCH₃, CO₂CH₃) in situ with cyclohexyl isocyanide. While 1a , 1b and 2a , 2b were characterized by elemental analysis and spectroscopy, 1b was further characterized by X‐ray crystallography.     

Structural studies of diiron complexes with monophosphine ligands tris(4-chlorophenyl)phosphine or diphenyl-2-pyridylphosphine

Four diiron dithiolate complexes with monophosphine ligands have been prepared and structurally characterized. Reactions of (μ-SCH₂CH₂S-μ)Fe₂(CO)₆ or [μ-SCH(CH₃)CH(CH₃)S-μ]Fe₂(CO)₆ with tris(4-chlorophenyl)phosphine or diphenyl-2-pyridylphosphine in the presence of Me₃NO·2H₂O afforded diiron pentacarbonyl complexes with monophosphine ligands (μ-SCH₂CH₂S-μ)Fe₂(CO)₅[P(4-C₆H₄Cl)₃] (1), (μ-SCH₂CH₂S-μ)Fe₂(CO)₅[Ph₂P(2-C₅H₄N)] (2), [μ-SCH(CH₃)CH(CH₃)S-μ]Fe₂(CO)₅[P(4-C₆H₄Cl)₃] (3), and [μ-SCH(CH₃)CH(CH₃)S-μ]Fe₂(CO)₅[Ph₂P(2-C₅H₄N)] (4) in good yields. Complexes 1–4 were characterized by elemental analysis, ¹H NMR, ³¹P{¹H} NMR and ¹³C{¹H} NMR spectroscopy. Furthermore, the molecular structures of 1–4 were confirmed by X-ray crystallography.     

Stereoselectivity in Diphos Addition to Molybdenum Complex with Pyridine‐2‐thionate (pyS) and η3‐Methallyl Coordinated Ligands

The conformational isomers endo‐ and exo‐[Mo{η³‐C₃H₄(CH₃)}(η²‐pyS)(CO)(η²‐diphos)] (diphos: dppm = {bis(diphenylphosphino)methane}, 2 ; dppe = {1,2‐bis(diphenylphosphino)ethane}, 3 ) are prepared by reacting the double‐bridged pyridine‐2‐thionate (pyS) complex [Mo{η³‐C₃H₄(CH₃)}(CO)₂]₂(η¹:η²:μ‐pyS)₂, 1 with diphos in refluxing acetonitrile. Stereoselectivity of the methallyl, C₃H₄(CH₃), ligand improves the formation of the exo‐conformation of 2 and 3 . Orientations and spectroscopy of these complexes are discussed.     

Syntheses of (η6-p-cymene)ruthenium(II) piano-stool amine complexes: molecular structure of [(η6-C10H14)RuCl2(H2N-C6H4-p-Cl)]

The dimeric complex [{(η⁶-p-cymene)Ru(μ-Cl)Cl}₂] (1) reacts with S,N-donor Schiff base ligands, para-substituted S-(thiophen-2-ylmethylene)phenylamines in methanol to give mononuclear amine complexes of the type [(η⁶-p-cymene)RuCl₂(NH₂–C₆H₄–p-X)] {X?=?H (2a); X?=?CH₃ (2b); X?=?OCH₃ (2c); X?=?Cl (2d); Br (2e) X?=?NO₂ (2f), respectively} by hydrolysis of the imine group of the ligand after coordination to the metal. The complexes were characterized by analysis and IR and NMR spectroscopy. The molecular structure of [(η⁶-C₁₀H₁₄)RuCl₂(H₂N–C₆H₄–p-Cl)] (2d) was established by a single-crystal X-ray diffraction study.     

Cobalt (II) coordination polymers based on 3,5-dinitrobenzoate and flexible bis(benzimidazole) derivatives bearing different spacer lengths and substituents

Three new Co^II coordination polymers, namely [Co(DNBA)₂(pbdmbm)] (1), [Co₂(H₂O)₂(DNBA)₂(ebdmbm)₂] (2) and [Co₂(DNBA)₂(pbbm)₂] (3) have been obtained by hydrothermal reactions of Co^II with flexible bis(benzimidazole) ligands [1,1′-(1,3-propanediyl)bis(5,6-dimethylbenzimidazole) (pbdmbm), 1,1′-(1,2-ethanediyl)bis(5,6-dimethylbenzimidazole) (ebdmbm), 1,1′-(1,3-propanediyl)bis(benzimidazole) (pbbm)] plus 3,5-dinitrobenzoic acid (HDNBA). The complexes have been characterized by single crystal X-ray diffraction, elemental analyses, IR and TG. Complexes 1 and 3 exhibit one-dimensional chains composed of Co^II centers bridged by flexible bis(benzimidazole) ligands. Complex 2 is a three-dimensional NaCl-type supramolecular framework constructed from binuclear units, which are formed by two Co^II centers and two ebdmbm ligands. The spacer length and substituents on the bis(benzimidazole) ligands are crucial for the construction of these structures. The photoluminescence properties of the complexes and the cyclic voltammetry behavior of complex 1 are described.     

Syntheses, crystal structures and properties of two 1-D cadmium(II) coordination polymers based on 1,1′-(1,3-propanediyl)bis-1H-benzimidazole

The combination of framework-builders 1,1′-(1,3-propanediyl)bis-1H-benzimidazole (pbbm), Cd(II) ion and framework-regulator ClO₄⁻ or SO₄²⁻ provides two new coordination polymers [Cd(pbbm)₂(ClO₄)₂]_n(1) and {[Cd(pbbm)SO₄(H₂O)₂]·CH₃OH}_n(2). Both of them display 1-D chain framework, but their detailed structures are clearly different from each other. 1 displays a 1-D ribbon of rings framework, 2 features an interesting infinite 1-D looped chain structure composed of two kinds of rings, the smaller 8-membered ring and the larger 20-membered ring. The antimicrobial activities of the two polymers were tested by the agar diffusion method and the results indicated that they exhibited antimicrobial activities against bacterial strands. The measurement of the non-isothermal kinetics of the thermal decomposition of 2 reveals that there are at least three steps that occur in its decomposition process.     

Ruthenium(II) complexes of aroylhydrazones: structural,electrochemical and electrostatic interactions with DNA

Four Ru(II) complexes with tridentate ligands viz. (4-hydroxy-N′-(pyridin-2-yl-ethylene) benzohydrazide [Ru(L¹)(PPh₃)₂(Cl)] (1), N′-(pyridin-2-yl-methylene) nicotinohydrazide [Ru(L²)(PPh₃)₂(Cl)] (2), N′-(1H-imidazol-2-yl-methylene)-4-hydroxybenzohydrazide [Ru(L³)(PPh₃)₂(Cl)] (3), and N′-(1H-imidazol-2-yl-methylene) nicotinohydrazide [Ru(L⁴)(PPh₃)₂(Cl)] (4) have been synthesized and characterized. The methoxy-derivative of L³H (abbreviated as L³H*) exists in E configuration with torsional angle of 179.4° around C₇-N₈-N₉-C₁₀ linkage. Single crystal structures of acetonitrile coordinated ruthenium complexes of 1 and 3 having compositins as [Ru(L¹)(PPh₃)₂(CH₃CN)]Cl (1a) and [Ru(L³)(PPh₃)₂(CH₃CN)]Cl (3a) revealed coordination of tridentate ligands with significantly distorted octahedral geometry constructed by imine nitrogen, heterocyclic nitrogen, and enolate amide oxygen, forming a cis-planar ring with trans-placement of two PPh₃ groups and a coordinated acetonitrile. Ligands (L¹H-L⁴H) and their ruthenium complexes (1–4) are characterized by ¹H, ¹³C, ³¹P NMR, and IR spectral analysis. Ru(II) complexes have reversible to quasi-reversible redox behavior having Ru(II)/Ru(III) oxidation potentials in the range of 0.40–0.71 V. The DNA binding constants determined by absorption spectral titrations with Herring Sperm DNA (HS-DNA) reveal that L⁴H and 1 interact more strongly than other ligands and Ru(II) complexes. Complexes 1–3 exhibit DNA cleaving activity possibly due to strong electrostatic interactions while 4 displays intercalation.