Synthesis,crystal structures,and antimicrobial activities of hydrazone complexes of vanadium(V)

Two hydrazone ligands, (E)-N′-(3-bromo-2-hydroxybenzylidene)-2-methoxybenzohydrazide (HL^a) and (E)-N′-(2-hydroxy-3-methylbenzylidene)-2-methoxybenzohydrazide (HL^b), were prepared and characterized by IR, UV–vis, and ¹H NMR spectroscopy. The corresponding vanadium(V) complexes, 2[VOL^aL]·CH₃OH (1) and [VOL^bL] (2), where L is the monoanionic form of benzohydroxamic acid (HL), were prepared and characterized by IR and UV–vis spectroscopy, and single-crystal X-ray diffraction. Complex 1 crystallizes as the monoclinic space group P2₁/c, with unit cell dimensions a = 14.4161(16) Å, b = 14.0745(16) Å, c = 24.069(2) Å, β = 96.247(2), V = 4854.5(9) Å³, Z = 4, R₁ = 0.0541, wR₂ = 0.1423, Goof = 1.032. Complex 2 crystallizes in the orthorhombic space group Pbca, with unit cell dimensions a = 13.5906(6) Å, b = 18.1865(11) Å, c = 18.4068(11) Å, V = 4549.5(4) Å³, Z = 8, R₁ = 0.0549, wR₂ = 0.1397, Goof = 1.054. X-ray analysis indicates that the complexes are mononuclear octahedral vanadium(V) complexes. The thermal behavior of the complexes was investigated. The hydrazone ligands and their complexes were also evaluated for their antibacterial (Bacillus subtilis, Staphylococcus aureus, Escherichia coli, and Pseudomonas fluorescence) and antifungal (Candida albicans and Aspergillus niger) activities using the MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide) assay. The two complexes have moderate to good activities against B. subtilis and S. aureus, and 1 has moderate activity against E. coli.     

Syntheses,characterization and catalytic activities of half-sandwich ruthenium complexes with naphthalene-based Schiff base ligands

Four ruthenium(II) p-cymene complexes with naphthalene-based Schiff base ligands [Ru(p-cymene)LCl] (2a–2d) have been synthesized and characterized. The half-sandwich ruthenium complexes were characterized by ¹H and ¹³C NMR spectra, elemental analyses, and infrared spectrometry. The molecular structures of 2a, 2b, and 2c were confirmed by single-crystal X-ray diffraction. Furthermore, these half-sandwich ruthenium complexes are highly active catalysts for the hydrogenation of nitroarenes to anilines using NaBH₄ as the reducing agent in ethanol at room temperature.     

Synthesis and physiochemical studies on binuclear Cu(II) complexes derived from 2,6-[(N-phenylpiperazin-1-yl)methyl]-4-substituted phenols

Preparation of the ligands HL¹ = 2,6-[(N-phenylpiperazin-1-yl)methyl]-p-ethylphenol; HL² = 2,6-[(N-phenylpiperazin-1-yl)methyl]-p-methoxyphenol and HL³ = 2,6-[(N-phenylpiperazin-1-yl)methyl]-p-nitrophenol are described together with their Cu(II) complexes with different bridging units. The exogenous bridges incorporated into the complexes are: hydroxo [Cu₂L(OH)(H₂O)₂](ClO₄)₂.H₂O (L¹=1a, L² =1b, L³ =1c), acetato [Cu₂L(OAc)₂]ClO₄.H₂O (L¹ =2a, L² =2b, L³ =2c) and nitrito [Cu₂L¹(NO₂)₂(H₂O)₂]ClO₄.H₂O (L¹=3a, L² =3b, L³ =3c). Complexes1a,1b,1c and2a,2b,2c contain bridging exogenous groups, while3a,3b,3c possess only open μ-phenolate structures. Both the ligands and complexes were characterized by spectral studies. Cyclic voltammetric investigation of these complexes revealed that the reaction process involves two successive quasireversible one-electron steps at different potentials. The first reduction potential is sensitive to electronic effects of the substituents at the aromatic ring of the ligand system, shifting to positive potentials when the substituents are replaced by more electrophilic groups. EPR studies indicate very weak interaction between the two copper atoms. Various covalency parameters have been calculated.     

Synthesis of new ruthenium(II) complexes derived from labile nitrile ligands: an alternative route to the preparation of trans-dichlorotetrakis(diphenylphosphine)ruthenium(II)

New ruthenium(II) complexes containing labile nitrile ligands have been prepared by treatment of either the polymer [{RuCl₂(COD)}_x] (COD = cycloocta-1,5-diene) (1) or its derivative [RuCl₂(COD)(NCCH₃)₂]·NCCH₃ (2) with the appropriate nitrile ligands in refluxing acetonitrile under argon. A new route to synthesis of trans-dichlorotetrakis(diphenylphosphine)ruthenium(II) (7) was also reported. A redetermination of the structure of 7 was undertaken and X-ray crystallographic data revealed that the complex crystallizes in the triclinic space group P-1 with unit cell dimensions a = 12.7016(9) Å, b = 13.0847(10) Å, c = 14.1498(10) Å, α = 101.46(3)°, V = 2080.6(3) Å³, Z = 2 and R = 0.0309. Its polymorph 7′ was also obtained. The crystal structure of 4 was also determined. This complex crystallizes in the monoclinic space group C2/c with unit cell dimensions a = 27.0510(3) Å, b = 11.0984(13) Å, c = 13.0450(16) Å, α = 90°, V = 3886.5(8) Å³, Z = 8 and R = 0.0282.     

Synthesis,characterization, electrochemical and theoretical study of substituted phenyl-terpyridine and pyridine-quinoline based mixed chelate ruthenium complexes

In the present work, we report two methoxy-substituted phenyl-terpyridine ruthenium complexes with pyridine carboxyquinoline and NCS as ancillary ligands, [Ru(OMePhtpy)(pcqH)(NCS)](PF₆) (1) and [Ru(triOMePhtpy)(pcqH)(NCS)](PF₆) (2) (where OMePhtpy = (4′-(4-methoxy)phenyl-2,2′:6′,2″-terpyridine, triOMePhtpy = (4′-(3,4,5-trimethoxy)phenyl-2,2′:6′,2″-terpyridine and pcqH = pyridine-carboxyquinoline). Both complexes have been characterized by spectroscopic techniques e.g., mass, ¹H-NMR and FTIR. UV–vis spectrophotometric and electrochemical studies for both complexes have been performed. The substitution pattern of the –OMe groups have been successfully utilized to tune the redox potential of the metal complexes. On the anodic side of cyclic voltammogram, 1 and 2 show an irreversible wave corresponding to Ru^II/III couple at 0.95 and 0.85 V, respectively. The lower Ru^II/III oxidation potential for 2 may be attributed to increased electron density on ruthenium due to three (+R) methoxy–groups appended to the phenyl moiety of triOMePhtpy. DFT optimization of structure and energy calculation reveals that in both complexes, HOMO is metal- and thiocyanate-based, whereas the LUMO is based on pcqH. Correlation of TDDFT results with experimental electronic spectrum indicates that bands at 502 nm (1) and 528 nm (2) are of MLLCT character from ruthenium-thiocyanate to pcqH.     

Ruthenium(II) carbonyl complexes of P,P and P,O donor diphosphine ligands,Ph2P(CH2)nPPh2 and Ph2P(CH2)nP(O)Ph2, n = 2, 3 and their activities in catalytic transfer hydrogenation reactions

The polymeric precursor [RuCl₂(CO)₂]_n reacts with the ligands, P∩P (a, b) and P∩O (c, d), in 1:1 M ratio to generate six-coordinate complexes [RuCl₂(CO)₂(?²-P∩P)] (1a, 1b) and [RuCl₂(CO)₂(?²-P∩O)] (1c, 1d), where P∩P: Ph₂P(CH₂)_nPPh₂, n = 2(a), 3(b); P∩O: Ph₂P(CH₂)_nP(O)Ph₂, n = 2(c), 3(d). The complexes are characterized by elemental analyses, mass spectrometry, thermal studies, IR, and NMR spectroscopy. 1a–1d are active in catalyzed transfer hydrogenation of acetophenone and its derivatives to corresponding alcohols with turnover frequency (TOF) of 75–290 h^?1. The complexes exhibit higher yield of hydrogenation products than catalyzed by RuCl₃ itself. Among 1a–1d, the Ru(II) complexes of bidentate phosphine (1a, 1b) show higher efficiency than their monoxide analogs (1c, 1d). However, the recycling experiments with the catalysts for hydrogenation of 4-nitroacetophenone exhibit a different trend in which the catalytic activities of 1a, 1b, and 1d decrease considerably, while 1c shows similar activity during the second run.     

Synthesis and characterization of half-sandwich ruthenium(II) complexes with N-alkyl pyridyl-imine ligands and their application in transfer hydrogenation of ketones

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 [(η⁶-arene)RuCl(C₅H₄N-2-CH=N-R)]PF₆, with arene = C₆H₆, R = iso-propyl (1a), tert-butyl (1b), cyclohexyl (1c), cyclopentyl (1d) and n-butyl (1e); arene = p-cymene, R = iso-propyl (2a), tert-butyl (2b). The complexes were fully characterized by ¹H NMR and ¹³C NMR, UV–Vis and IR spectroscopies, elemental analyses, and the single-crystal X-ray structures of 2a and 2b have been determined. The single-crystal molecular structure revealed both compounds with a pseudo-octahedral geometry around the Ru(II) center, normally referred to as a piano stool conformation, with the pyridyl-imine as a bidentate N,N ligand. The activity of all complexes in the transfer hydrogenation of cyclohexanone in the presence of NaOH and iso-propanol is reported, the compounds showing turnover numbers of close to 1990 and high conversions. Complex 2b was also shown to be very effective for a range of aliphatic and cyclic ketones, giving conversions of up to 100 %.     

A new phenylimidorhenium(V) compound containing the 2-[(2-hydroxyethylimino)methyl]phenol Schiff-base ligand: experimental and theoretical aspects

Reaction of equimolar trans-[Re(NPh)(PPh₃)₂Cl₃] with H₂L, a 1?:?1 Schiff-base condensate of salicylaldehyde and ethanolamine, in chloroform gives trans-[Re(NPh)(HL)(PPh₃)Cl₂] (1a) in good yield. 1a has been characterized by C, H, and N microanalyses, FTIR and UV–vis spectra. The X-ray crystal structure of 1a reveals that it is an octahedral trans-Cl,Cl phenylimidorhenium(V) complex. The rhenium center has an ‘N₂OCl₂P’ coordination sphere. 1a crystallizes in the monoclinic space group P2₁/c with a = 11.2391(5), b = 16.4848(7), c = 16.3761(8) Å, V = 3034.0(2) ų and Z = 4. The electrochemical aspects of 1a have been studied. Electrochemical studies of 1a in dichloromethane show a quasi-reversible Re(V) to Re(VI) oxidation at 1.128 V versus Ag/AgCl. This redox potential reasonably matches the calculated redox potential, 1.186 V versus Ag/AgCl. Geometry optimization of the trans-Cl,Cl 1a vis-à-vis its cis analog, cis-Cl,Cl 1b, have been performed at the level of density functional theory (DFT). It is revealed that 1a is more stable than 1b by 21.6 kcal per mole of energy in the gas phase.     

Two copper(II) complexes of curcumin derivatives: synthesis,crystal structure and in vitro antitumor activity

Two Cu(II) complexes of curcumin derivatives, formulated as CuL ₂ ^a (1) and CuL ₂ ^b (2) [HL^a = 1,7-bis(4-ethyloxy-3-methoxy-phenyl)-1,6-heptadiene-3,5-dione and HL^b = 1,7-bis(4-butyloxy-3-methoxy-phenyl)-1,6-heptadiene-3,5-dione], have been synthesized and characterized by single-crystal X-ray diffraction, along with physicochemical and spectroscopic methods. In both complexes, each Cu(II) center is surrounded by four oxygen atoms from two β-diketone ligands in a square planar geometry. Complex 1 forms a 2D layer structure through intermolecular π–π stacking interactions, as well as weak coordination interactions between the Cu and O atoms of the solvent 1,4-dioxane molecules. Complex 2 displays a 1D column structure stabilized by intermolecular π–π stacking interactions. MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] assays were used to evaluate the cytotoxicities of these complexes against three human cancer cell lines. The results show that the Cu(II) complexes exhibit more potent inhibition tumor growth in comparison with the free ligands.     

Theoretical investigation of different reactivities of Fe(IV)O and Ru(IV)O complexes with the same ligand topology

The structures and mechanisms for hydrogen abstraction from isopropylbenzene for four high-valence complexes, cis-β-[Fe^IV(O)(BQCN)]²⁺ (Fe-2b and Fe-2b-2) and cis-β-[Ru^IV(O)(BQCN)]²⁺ (Ru-2b and Ru-2b-2) (BQCN = N,N′-dimethyl-N,N′-bis(8-quinolyl)-cyclohexanediamine), were investigated using density functional theory. Of the two iron complexes, Fe-2b-2 has more exposed FeO units than Fe-2b, with iron being further out of the equatorial plane because of the steric interaction of the same ligand topologies with the iron-oxo group trans to a quinolyl or amine nitrogen. The contribution of BQCN to Fe-2b is higher than the contribution to Fe-2b-2 as shown by the density-of-states spectra. The iron isomers can abstract hydrogen from isopropylbenzene via two-state reactivity patterns, whereas the ruthenium isomers react with isopropylbenzene via a single-state mechanism. In the gas phase, the relative reactivity exhibits the trend Fe-2b > Fe-2b-2, whereas with the addition of the ZPE correction and the SMD model, the relative reactivity follows Fe-2b-2 > Fe-2b. For the ruthenium complexes, the relative reactivity follows the trend Ru-2b-2 > Ru-2b in both the gas phase and solvent. Thus, the same ligand topologies with the metal-oxo group trans to a different nitrogen affect the reactivities of the iron and ruthenium complexes.     

Structure,DNA-binding interaction and antitumour activity of two novel complexes coordinated by tridentate 1,3-bis(benzimidazol-2-yl)-2-oxapropane ligand

Two novel DNA-intercalating complexes, [Cd(hipa)(bbiop)] _n (1) and [Ni(ada)(bbiop)] _n ·2H₂O (2) with hipa, ada and potentially tridentate ligand bbiop (bbiop, 1,3-bis(benzimidazol-2-yl)-2-oxa-propane; hipa, 5-hydroxyisophthalate; ada, aniline-N,N-diacetate), have been synthesised under hydrothermal methods and structurally characterised by single crystal X-ray diffraction analysis, elemental analysis, UV–vis spectrum and fluorescent spectrum. The bbiop ligand exists as chelating-tridentate μ₁-(η₃–N₁, N₂, O₆) coordination fashion. In addition, their in vitro cytotoxicities towards four selected tumour cell lines have been evaluated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide method. Complex 1 exhibits the most dramatic inhibitory effect on MG-63, and its inhibition rate is higher than that of its free ligands, H₂bbiop and hipa, indicating significantly enhanced effect after forming complex. On the basis of the combination of UV–vis absorption and fluorescence titrations, complex 1 can interact with the base pairs of double-helical DNA via an intercalative mode with intrinsic binding constant, K _b, of 4.62 × 10⁷, presenting the high DNA-binding affinity.     

Vanadium complexes with quadridentate Schiff bases

The Schiff base ligands N,N′-(±)-trans-bis(3,5-dichloro-2-hydroxyacetophenone)-1,2-cyclohexanediamine (H₂L¹) and N,N′-(±)-trans-bis(5-chloro-4-methyl-2-hydroxyacetophenone)-1,2-cyclohexanediamine (H₂L²) were derived from the condensation of trans-1,2-diaminocyclohexane with 3,5-dichloro-2-hydroxyacetophenone or 5-chloro-4-methyl-2-hydroxyacetophenone, respectively. Both these ligands formed well-defined complexes with vanadium (IV) and (V) under suitable experimental conditions. These complexes have been characterized by elemental analysis, molar conductivity, magnetic moments, infrared, electronic spectra, ESR, X-ray diffraction, and thermogravimetric analysis. X-ray diffraction study of [VO(L²)]·H₂O complex indicated its monoclinic crystal system with a = 9.8525, b = 23.6271, c = 9.0904 Å, and β = 97.87°. The complexes [VO(L¹)]·H₂O and [VO(L²)]·H₂O have been examined as catalysts for epoxidation of styrene in the presence of hydrogen peroxide as oxidant. The IR spectral data suggest that both the ligands behave as dibasic tetradentate chelating agent with ONNO donor atoms sequence toward cental metal ion.     

Photochemical reactions of metal carbonyls with heteroaromatic methanesulfonylhydrazone-based ligands

Three new heteroaromatic methanesulfonylhydrazone derivatives: thiophene-2-carboxy aldehydemethanesulfonylhydrazone (msh 1), 2-acetylthiophenemethanesulfonylhdrazone (msh 2), and 2-acetyl-5-methylthiophenemethanesulfonylhydrazone (msh 3) were prepared and their metal carbonyl complexes ([M(CO)₅(msh 1)] M = Cr, 1a; Mo, 1b; W, 1c); ([M(CO)₅(msh 2)] M = Cr, 2a; Mo, 2b; W, 2c); and ([M(CO)₅(msh 3)] M = Cr, 3a; Mo, 3b; W, 3c) were synthesized by photochemical reactions of [M(CO)₆ M = Cr, Mo, W] with msh 1–3. Heteroaromatic methanesulfonylhydrazones, msh 1–3, and their metal carbonyl complexes were characterized by elemental analysis, mass spectrometry, IR, and ¹H and ¹³C–{¹H} NMR spectroscopy. According to all the spectroscopic data, msh 1–3 are monodentate and coordinate via thiophene ring sulfur. The msh 1–3 must act as two-electron donors to satisfy the 18-electron rule.     

Efficient and versatile catalysis for β-alkylation of secondary alcohols through hydrogen auto transfer process with newly designed ruthenium(II) complexes containing ON donor aldazine ligands

A new series of ruthenium(II) carbonyl complexes, [RuCl(CO)(EPh₃)₂(L_1-2)] (1–4) (E = P or As; H₂L₁ = salicylaldazine, H₂L₂ = 2-hydroxynaphthaldazine), have been assembled from ruthenium(II) precursors [RuHCl(CO)(EPh₃)₃] and bidentate ON donor Schiff base ligands (H₂L_1-2). Both ligands and their new ruthenium(II) complexes have been characterized by elemental analyses, spectroscopic methods (UV, IR, NMR (¹H, ¹³C, ³¹P) as well as ESI mass spectrometry. The molecular structures of H₂L₁ and 1 have been confirmed by single crystal X-ray diffraction. Based on the above studies, an octahedral coordination geometry around the metal center has been proposed for 1–4. To investigate the catalytic effectiveness of 1–4, the complexes have been used as catalysts in β-alkylation of secondary alcohols with primary alcohols and synthesis of quinolines. The effect of solvent, time, base, catalyst loading, and substituent of the ligand moiety on the reaction was studied. Notably, 1 was a more efficient catalyst toward alkylation of a wide range of alcohols and quinolines synthesis. The reusability of the catalyst was checked and the results showed up to six catalytic runs without significant loss of activity.     

Ruthenium piano-stool complexes bearing imidazole-based PN ligands

A variety of piano-stool complexes of cyclopentadienyl ruthenium(II) with imidazole-based PN ligands have been synthesized starting from the precursor complexes [CpRu(C₁₀H₈)]PF₆, [CpRu(NCMe)₃]PF₆ and [CpRu(PPh₃)₂Cl]. PN ligands used are imidazol-2-yl, -4-yl and -5-yl phosphines.Depending on the ligand and precursor different types of coordination modes were observed; in the case of polyimidazolyl PN ligands these were κ¹P-monodentate, κ²P,N-, κ²N,N- and κ³N,N,N- chelating and μ-κP:κ²N,N-brigding. The solid-state structures of [CpRu(1a)₂Cl ]·H₂O (5^.H₂O) and [{CpRu(μ-κ²-N,N-κ’¹-P-2b)}₂](C₆H₅PO₃H)₂(C₆H₅PO₃H₂)_2, a hydrolysis product of the as well determined [{CpRu(2b)}₂](PF₆)₂^.2CH₃CN (7b^.2CH₃CN) were determined (1a = imidazol-2-yldiphenyl phosphine, 2b = bis(1-methylimidazol-2-yl)phenyl phosphine, 3a = tris(imidazol-2-yl)phosphine). Furthermore, the complexes [CpRu(L)₂]PF₆ (L = imidazol-2-yl or imidazol-4-yl phosphine) have been screened for their catalytic activity in the hydration of 1-octyne.     

Synthesis,characterization, crystal structure,and DNA binding of two copper(II)–hydrazone complexes

Two new Cu(II)–hydrazone complexes, [Cu(L)(Hbpe)ClO₄]·ClO₄·[Cu(L)Cl] (1) and [Cu(HL)₂]·1.5ClO₄·0.5OH (2) (where HL?=?(E)-N′-(1-(pyridine-2-yl)ethylidene)benzohydrazide and bpe = trans-1-(2-pyridyl)-2-(4-pyridyl)ethylene), have been synthesized and characterized by physicochemical methods. The structures of the complexes have been established by single-crystal X-ray diffraction direct methods, which reveal that the metal ions have distorted square-pyramidal and square-planar geometries in 1, and a distorted octahedral geometry in 2. DNA binding of HL, 1, and 2, performed by UV–vis titration in tris-buffer medium, yielded binding constants, which are 9.5 × 10³, 1.88 × 10⁴, and 4.66 × 10⁴ M^?1, respectively. Viscosity measurements suggest a surface or groove-binding mode of interaction between CT-DNA with HL, 1, and 2.     

Synthesis,Recognition of Metal Ions of Salicylidenimine Functionalized p-tert-Butylcalix[n]arene-core Dendrimers

A series of salicylidenimine functionalized p-tert-butylcalix[n]arene-core dendrimers 7a–b were synthesized in higher yields by divergent method from the corresponding ethyl p-butylcalix[n]arylacetates 2a–b (n = 6, 8). 2a–b were first treated with excess of 1,6-diaminohexane to give amide derivatives with free amine terminal groups 3a–b, which in turn reacted with salicylaldehyde in alcohol to yield the first generation of Schiff bases 4a–b. 3a–b reacted with ethyl acrylate, ammonolized with 1,6-diaminohexane and condonsated with salicylaldehyde successfully to give the second generation of Schiff bases 7a–b. The extraction and binding properties of the dentritic Schiff bases 4a–b and 7a–b for several kinds of metal ions were studied with UV–Vis spectroscopy and atomic absorption spectroscopy. In which they showed a great affinity for soft Cu^2 +  ions and formed 1:1 or 1:2 stoichiometric complexes.     

Synthesis and characterization of dinuclear (Hedta)Ru(III) complexes with N-heterocyclic ligands: magnetic properties and DNA-binding studies

Two ruthenium(III) complexes containing ethylenediaminetetraacetate(edta), viz. [{Ru(Hedta)}₂L]·xH₂O L = 4,4′-bipyridine(bpy) (1) and 4,4′-azopyridine(Azpy) (2), have been synthesized by the reaction between K[Ru(Hedta)Cl]·1.5H₂O and the corresponding N-heterocycles. Complex 1 was determined by single-crystal X-ray diffraction. The products were characterized by IR, UV–vis, cyclic voltammetry, and magnetic techniques. Their DNA-binding activities were investigated using electronic absorption spectroscopic methods and ?uorescence quenching; the experimental results show that these two ruthenium complexes may bind to CT-DNA through intercalation modes.     

Syntheses,structural determination,and binding studies of nine-coordinate multinuclear (mnH)2[EuIII(egta)]2·6H2O and binuclear (mnH)4[EuIII2(dtpa)2]·6H2O

Two lanthanide complexes, (mnH)₂[Eu^III(egta)]₂·6H₂O (1) (H₄egta = ethyleneglycol-bis-(2aminoethylether)-N,N,N′,N′-tetraacetic acid) and (mnH)₄[Eu^III₂(dtpa)₂]·6H₂O (2) (H₅dtpa = diethylenetriamine-N,N,N′,N″,N″-pentaacetic acid), have been synthesized and characterized by FT-IR spectroscopy, thermal analysis, and single-crystal X-ray diffraction. X-ray diffraction reveals that 1 is multinuclear nine-coordinate and crystallizes in the monoclinic crystal system with space group C2/c. The obtained cell dimensions are a = 38.513(3)?Å, b = 13.5877(8)?Å, c = 8.7051(5)?Å, β = 99.6780(10)°, and 4490.6(5)?ų. Each methylamine (mnH⁺) cation in 1, through hydrogen bonds, connects three adjacent [Eu^III(egta)]^? anions. The [Eu^III(egta)]^? anions connect one another forming a 1-D multinuclear zigzag chain structure along the c-axis. Complex 2 is nine-coordinate binuclear structure with tricapped trigonal prismatic conformation and crystallizing in the monoclinic crystal system, but with space group P2₁/n. The obtained cell dimensions are a = 9.9132(8)?Å, b = 24.1027(18)?Å, c = 10.7120(10)?Å, β = 109.1220(10)°, and 2418.2(3)?ų. For 2, there are two kinds of methylamine cations (mnH⁺) connecting [Eu^III₂(dtpa)₂]^4? complex anions and lattice waters through hydrogen bonds, leading to formation of a 2-D ladder-like layer structure.