Hydrazine Ligand Research Articles

Self-Assembled Lanthanide Supramolecular Helicates: Efficient Catalysts for Synthesis of Heterocyclic Scaffolds

Geometrically unsaturated binuclear double-stranded metallohelicates constructed with pyridyl hydrazine ligands and lanthanide metal ions via metal-templated self-assembly. The single-crystal X-ray analysis suggests the formation of helical assembly through its coordination with pyridyl, azomethine nitrogen’s and ketonic oxygen with metal ions. Lanthanide ions are known to possess multiple coordination sites, other labile sites are occupied with solvents and anions. The lanthanide helicates are exhaustively characterized and adopted as a catalyst to synthesize benzothiazole scaffolds starting from 2-fluoroaniline and phenyl isothiocyanate substrates via tandem thiourea intermediate/cyclization pathway. The mechanistic investigation suggests the reaction proceeds via the nucleophilic aromatic substitution pathway. The protocols are extended for the synthesis of drug molecules such as Riluzole and Dimazole.

Tautomerization of diazenehydrazine via single proton tautomerization, spectral, XRD/HSA-interactions, optical and DFT/TD-DFT of new hydrazine ligand

A novel methyl (Z)-2-(2-(2-oxonaphthalen-1(2H)-ylidene)hydrazineyl)benzoate isomer ligand has been prepared instead of (E)-methyl 2-((2-hydroxynaphthalen-1-yl)diazenyl)benzoate isomer in very good yield. The tautomerization of diazene to hydrazine was computed via DFT; the single proton tautomerization S(6) process was confirmed by XRD. Moreover, the XRD-crystal measurements supported the hydrazine form as the preferred kinetic isomer; the structure of the desired ligand was also examined by IR, UV–vis., Carbon, Hydrogen and Nitrogen elemental analysis (CHN-EA), and NMR. Hirshfeld surface analysis (HSA) computation was performed to support the lattice interactions resulting by X-ray diffraction (XRD) measurement. Furthermore, the time-dependent density functional theory (TD-DFT) and B3LYP/IR computation were used to support the UV–visible as well as FT-IR experimental results.

Structural and theoretical exploring of noncovalent interactions in Chlorido- and Nitrito-rhenium(I) tricarbonyl complexes bearing 2,3-Butadiene-bis(2-nitrobenzylidene)hydrazine Ligand: Intramolecular Re–κ1-endo-ONO(lone pair)…π*(C[tbnd]O) interaction

Herein, we report the synthesis, characterization and combined structural and full computational analysis of noncovalent interactions in a new hydrazine ligand and its two chlorido- and endo-nitrito-rhenium(I) tricarbonyl complexes. The analysis of crystal structures has been accompanied by comprehensive computational studies of the noncovalent interactions utilizing the quantum theory of atoms in molecules (QTAIM), natural bond orbitals (NBO), independent gradient model (IGM), and electron localization function (ELF) to shed light on the nature of the interactions. On the other hand, comprehensive energy decomposition analysis (EDA) by extended transition state coupled with natural orbitals for chemical valence (ETS-NOCV) scheme in a series of crystallographically retrieved dimers of the complexes was done to unveil the physical origin of these interactions and the factors affecting the interaction strength. In case of the Re- κ1-nitrito complex, the Interacting Quantum Atoms (IQA) scheme was used for detailed analysis of the interesting intramolecular Re–κ1-endo-ONO(lone pair)…π* (CO) interaction in the nitrito complex.

Synthesis, characterization, X-ray crystal structure and Hirshfeld surface analysis of Ni(II) complex of 1,2-bis(pyridin-2-ylmethylene)hydrazine

We report the synthesis, characterization, X-ray crystal structure and Hirshfeld surface analysis of Ni(II) perchlorate complex (1, Ni2L3·4ClO4·2CH3CN) of 1,2-bis(pyridin-2-ylmethylene)hydrazine (L) ligand. The X-ray crystallographic study of complex 1 reveals that in the presence of Ni(II) ions,the ligand L forms a dimeric triple helix with a Ni(II)-Ni(II) distance of 3.794 Å. Crystal data for C40H36Cl4N14Ni2O16: Monoclinic, space group P21/c (no. 14), a = 20.7558(19) Å, b = 13.1937(12) Å, c = 20.0181(18) Å, β = 96.9510(10)°, V = 5441.6(9) Å3, Z = 4, T = 293.15 K, μ(MoKα) = 0.965 mm-1, Dcalc = 1.498 g/cm3, 38075 reflections measured (1.976° ≤ 2Θ ≤ 43.728°), 6557 unique (Rint = 0.0695, Rsigma = 0.0466) which were used in all calculations. The final R1 was 0.0518 (I > 2σ(I)) and wR2 was 0.1270 (all data). The Hirshfeld surface analysis of complex 1 shows that C···H, H···H, N···H and O···H interactions of 10.9, 26.4, 6.7, and 33.4%; respectively, which exposed that the main intermolecular interactions were H···H intermolecular interactions.

Syntheses, Characterization, and X-ray Crystal Structure of Binuclear Lanthanide Complexes Assembled with Schiff Base and Acetate

Herein we reported the binuclear complexes of the 1-(pyridin-2-yl)-2-(pyridin-2-ylmethylene)hydrazine ligand (HL) [Ln2(HL)2(CH3COO)6].n(H2O) (Ln = Y, Pr, Gd and Er). The binuclear complexes are characterized by IR and physical measurement. Spectroscopic evidence indicated that the Schiff base HL behave an N3 coordination tridentate ligand. The complexes are formulated as [{Ln(1-(pyridin-2-ylmethylidene-kN)-2-(pyridin-2-yl-kN)hydrazine-kN1)(h2-OOCH3)2}{h1:h2:m2-OOCH3}2{Ln(1-(pyridin-2-ylmethylidene-kN)-2-(pyridin-2-yl-kN)hydrazine-kN1))(h2-OOCH3)2}].n(H2O). The structure of the praseodymium complex was elucidated by X-ray diffraction analysis. Suitable crystals were grown by slow evaporation of methanol solution. The asymmetric unit of the compound contains two neutral ligand molecules, two Pr3+ ions, four acetate anions acting in h2-OOCH3 mode, two acetate anions acting in h1:h2:m2-OOCH3 mode, and three uncoordinated water molecules. The praseodymium atom is ten coordinated and the coordination sphere is best described as a distorted bicapped square antiprism. The PrIII···PrIII distance is 4.2777(6) Å and the bridging angle Pr—O—Pr and O—Pr—O are respectively 115.8(3)° and 64.2(3)°. The structure is consolidated by intra and intermolecular hydrogen bond.

Antitumoral Properties of a Pincer-Type Isonicotinohydrazone-Hg(II) Complex

Objective: The aim of this study was to evaluate the antitumoral properties of the novel Hg(SCN)2 complex of a pincer-type isonicotinohyrazone ligand (PTIH). Materials and Methods: Hydrazine ligands were prepared through a Schiff base condensation between the 2-Acetylpyridine and isonicotinoyl acid hydrazide. PTIH was synthetized by a branch tube method using Hg(SCN)2. In vitro cell killing activity, the induction of apoptosis, the influence on motility, and the effects on mRNA expression to a motility-related gene (E-cadherin) of PTIH were evaluated in A549, HepG2, HUH7 cancer cell lines, and BEAS2B non-cancer cell line. Results: PTIH was found to be cytotoxic to cancer cells, compared to non-cancers, and induced apoptosis. Additionally, it suppressed cell migration in A549 cells, leading to an increase in the levels of E-cadherin mRNA expression, and decreased colony formation in HepG2 and HUH7 cells. Through UV titration studies, it was determined that PTIH showed albumin binding and interacted with DNA by electrostatically and/or groove binding. Conclusion: PTIH exerted more cytotoxic effects in some cancer cells than in normal cells. This feature and other anticancer properties make it a promising agent.

Charge‐Transfer Effects of Organic Ligands on Energy Storage Performance of Oxide Nanoparticle‐Based Electrodes

AbstractOne of the most difficult challenges related to pseudocapacitive nanoparticle (PC NP)‐based energy storage electrodes with theoretically high capacity is to overcome the sluggish charge‐transfer kinetics that result from the poorly conductive PC NPs and bulky/insulating organics (i.e., organic ligands and/or polymeric binders) within the electrodes. Herein, it is reported that physical/chemical functionalities of organic ligands and their molecular‐scale coating onto NPs have considerable effects on the rate capability and capacity of oxide NP‐based pseudocapacitor electrodes. For this study, pseudocapacitive iron oxide (Fe3O4) NPs are layer‐by‐layer (LbL)‐assembled with conductive indium tin oxide (ITO) NPs using various types of organic ligands (or linkers). In particular, hydrazine ligands, which have extremely small molecular size and strong chemical reducing properties, can effectively remove bulky organic ligands from the NP surface, and thus reduce the separation distance between neighboring NPs. Simultaneously, the hydrazine ligands significantly increase the number of oxygen vacancies on Fe3O4 and ITO NPs during LbL deposition, which markedly enhances the rate capability and capacitance of the electrodes compared to other organic ligands with bulky size and/or without reducing properties. This approach can provide a fundamental basis for developing and designing various high‐performance electrochemical electrodes based on metal oxide NPs.

Redox-Controlled and Reversible N-N Bond Forming and Splitting with an IronIV Terminal Imido Ligand.

Oxidation of the low-spin FeIV imido complex [{(tBupyrr)2py}Fe═NAd] (1) ((tBupyrr)2py2- = 2,6-bis(3,5-di-tert-butyl-pyrrolyl)pyridine, Ad = 1-adamantyl) with AgOAc or AgNO3 promotes reductive N-N bond coupling of the former imido nitrogen with a pyrrole nitrogen to form the respective ferric hydrazido-like pincer complexes [{(tBupyrrNAd)(tBupyrr)py}Fe(κ2-X)] (X = OAc-, 2OAc; NO3-, 2NO3). Reduction of 2OAc with KC8 cleaves the N-N bond to reform the FeIV imido ligand in 1, whereas acid-mediated demetalation of 2OAc or 2NO3 yields the free hydrazine ligand [(tBupyrrNHAd)(tBupyrrH)py] (3), the latter of which can be used as a direct entry to the iron imido complex when treated with [Fe{N(SiMe3)2}2]. In addition to characterizing these Fe systems, we show how this nitrene transfer strategy can be expanded to Co for the one-step synthesis of Co{(tBu-NHAdpyrr)(tBupyrr)py}] (4) ((tBu-NHAdpyrr)(tBupyrr)py2- = 2-(3-tBu-5-(1-adamantylmethyl-2-methylpropane-2-yl)-pyrrol-2-yl)-6-(3,5-tBu2-pyrrol-2-yl)-pyridine).

Electro-switching of first hyperpolarizability of metallorganic complexes via ligand reduction/oxidation

We report electro-switching of first hyperpolarizability (β) in monometallic (1) and bimetallic (2) Re(I) complexes containing 1,2-bis(pyridine-2-yl methylene)hydrazine (pymh) ligand. Both two- and three-state switching of β have been achieved by one- and two-electron reductions of the pymh ligand using, in situ, second harmonic light scattering (SHLS) from solution. We have shown that pymh reductions lead to an increase in β and this is due to reorganization of the molecular orbital energy levels subsequent to electron injection into the ligand orbitals and appearance of ligand to metal charge transfer (LMCT) bands closer to one and two-photon resonances at experimental wavelength.

Versatile formation of Ru(II) hydrazone complexes: Structure, theoretical studies and catalytic activity in α-alkylation

New 1-(anthracen-10-yl)methylene)-2-(benzo[d]thiazol-2-yl)hydrazine (BHA) and 1-(anthracen-10-yl)methylene)-2-(quinolin-2-yl)hydrazine (QHA) ligands were reacted with [RuHCl(CO)(E)3] (E = PPh3 or AsPh3) or [RuCl2(AsPh3)3] in a 1:1 mol ratio in chloroform-ethanol medium to synthesis new ruthenium complexes. All the new ruthenium complexes were analyzed by elemental analysis, IR, NMR (1H, 13C and 31P) spectroscopy, ESI-Mass spectrometry and single crystal XRD techniques. The single crystal XRD study reveals the octahedral geometry around the ruthenium ion. The study also shows that the ligands coordinate with the Ru metal as monoanionic bidentate N^N donors in complexes 1, 3 and 4 and as a neutral bidentate N^N donor in complex 2 by forming five or four member chelate rings. The intramolecular interactions in the crystal lattices were studied by Hirshfeld surface analysis. The results indicate that π-stacking contacts play an important role in the crystal lattices. DFT calculations were carried out to explain the solid structures of complexes 1–3. Moreover, the synthesized complexes were screened as catalysts for the α-alkylation of ketones with alcohols. The effect of various parameters, such as base, solvent, temperature, time, substituents and also catalyst loading, on the catalytic activity were analyzed. The results depict that the complex 3 was found to be an efficient catalyst for the synthesis of α-alkylation products.

Ru(II) complexes containing (2-(pyren-1-ylmethylene)hydrazinyl)benzothiazole: Synthesis, solid-state structure, computational study and catalysis in N-alkylation reactions

Reactions of (2-(pyren-1-ylmethylene)hydrazinyl)benzothiazole (L) with ruthenium(II) prefabricated precursors [RuHCl(CO)(EPh3)3] and [RuH2(CO)(EPh3)3] (E = P or As) afforded new Ru(II) complexes [RuCl(CO)(EPh3)2(L)] and [RuH(CO)(EPh3)2(L)] (E = P or As) (1–4). All the Ru(II) complexes (1–4) were characterized by IR, NMR spectroscopies, ESI-mass spectrometry and elemental analyses. The solid-state structures of Ru(II) complexes (2 and 3) were established by single crystal X-ray analyses and revealed distorted octahedral geometries around the ruthenium(II) ion and mono anionic bidentate N^N coordination mode for hydrazine ligand. The Ru(II) complexes 2 and 3 were also analyzed using Hirshfeld surface analysis and DFT calculations. Moreover, all the complexes (1–4) were utilized in the N-alkylation reactions of amines using alcohol. Complex 3 was found to be highly active towards N-alkylation of different aromatic amines with alcohol.

High local coordination symmetry around the spin center and the alignment between magnetic and symmetric axes together play a crucial role in single-molecule magnet performance.

A tetradentate 8-hydroxyquinoline-based acyl hydrazone ligand (HL1 = 8-hydroxyquinoline-2-carboxaldehyde-(aminourea)hydrochloride) was elaborately used to construct a mononuclear dysprosium complex DyCl3HL1·CH3OH (1) with a nearly ideal pentagonal bipyramid coordination geometry (D5h) surrounding the Dy(iii) ion to achieve the significant performance of single-molecule magnets (SMMs). Meanwhile, the isolated high local symmetry center was successfully kept intact and further bridged to a series of double bipyramid systems by two phenolic oxygen atoms of the acyl hydrazone ligands (HL1 and HL2 = 8-hydroxyquinoline-2-carboxaldehyde-(benzoyl)hydrazine), with the formulae [Dy2Cl4(L1)2(CH3OH)2]·4C5H5N (2) and [Dy2Cl4(L2)2]·2CH3CN (3). In addition, the monodentate co-ligand anion was replaced by a larger sterically hindered ligand and a bidentate monovalent β-diketonate anion to generate [Dy2(tfo)4(L2)2(EtOH)2] (4), [Dy2(tta)4(L2)2(EtOH)2]·2(EtOH) (5) and [Dy2(dbm)4(L2)2(EtOH)2] (6) (tfo = trifluoromethanesulfonic acid, dbm = dibenzoylmethane, tta = 4,4,4-trifluoro-1-(2-thienyl)-1,3-butanedione) with eight-coordinate geometry. Strikingly, the dynamic magnetic measurements revealed that complexes 1-3 did not display the expected significant SMM performance albeit they had high local symmetry. In combination with ab initio calculation, the alignment of the coordination symmetric axis and the magnetic easy axis dominates the molecular magnetic anisotropy, and the magnetic easy axis could be modulated by the distribution of coordination atoms with different electrostatic properties.

Structural diversity of isothiocyanato Cd(II) and Zn(II) Girard’s T hydrazone complexes in solution and solid state: effect of H-bonding on coordination number and supramolecular assembly of Cd(II) complex in solid state

The isothiocyanato Zn(II) complex (1) and mixed isothiocyanato/thiocyanato Cd(II) complex (2) with the condensation product of 2-acetylpyridine and trimethylammoniumacetohydrazide chloride (Girard’s T reagent) (HLCl) were investigated both experimentally and theoretically. The crystal structures of both complexes showed tridentate N2O coordination of hydrazine ligand. In complex 1 square-pyramidal coordination surrounding of Zn(II) consists of deprotonated hydrazone ligand and two isothiocyanato ligands, while in octahedral Cd(II) complex ligand is coordinated without deprotonation as a positively charged species and coordination geometry is completed with two N-coordinated and one S-coordinated NCS− anions. NMR spectroscopy and molar conductivity results for Cd(II) and Zn(II) complexes indicated their instability in solution. DFT calculations were performed to explain coordination preference and stability of complexes 1 and 2 in solid state and in solution. The obtained Cd(II) complex is the first reported mononuclear pseudohalide/halide Cd(II) complex with quinoline-/pyridine-based hydrazone ligands possessing octahedral geometry in solid state. In this complex, H-bonding has significant impact on coordination number and supramolecular assembly in solid state.

Synthesis, X-ray crystal structure and DFT studies of cobalt(II) and vanadium(V) complexes with N,N,O-tridentate aroyl-hydrazone based ligand

A new aroyl-hydrazone, 2-pyridine carboxaldehyde-derived hydrazone ligand and its cobalt(II) (1) and vanadium(V) (2) complexes were prepared. The structures of these compounds were investigated using elemental analysis, spectral (IR, UV), and X-ray diffraction measurements. The electrochemical properties of the complexes were studied by cyclic voltammetry. The hydrazone ligand acted as tridentate and coordinated to vanadium and cobalt via N-imine, N-pyridine, and O-benzohydrazide atoms. The Co(II) complex crystallizes in the monoclinic system, space group P21/c, and has a binuclear structure. Chloride ions behave as the linking bridge and a tridentate hydrazine ligand HL and water as the terminal capping ligands. The central Co(II) ion has distorted octahedral geometry. The vanadium(V) complex crystallizes in the monoclinic crystal system, space group P21/n, and can be described as having highly distorted trigonal-bipyramidal coordination. The geometries and electronic properties of the complexes were also obtained using DFT and TD-DFT calculations.

Crystal structure of bis-(acetato-κ2O,O')di-aqua-[1-(pyridin-2-yl-methyl-idene-κN)-2-(pyridin-2-yl-κN)hydrazine-κN1]terbium(III) nitrate monohydrate.

In the title compound, [Tb(C2H3O2)2(C11H10N4)(H2O)2]NO3·H2O, the Tb3+ ion is nine-coordinated in a distorted tricapped trigonal-prismatic geometry by the three N atoms of the tridentate 1-(pyridin-2-yl-methyl-idene)-2-(pyridin-2-yl)hydrazine ligand, four carboxyl-ate O atoms of two chelating acetate groups and two O atoms of the coordinating water mol-ecules. The organic hydrazine ligand is disordered over two orientations with a refined occupancy ratio of 0.52 (3):0.48 (3). All bond lengths in the coordination environment of the Tb3+ ion are slightly larger than those observed in the isostructural Y3+ and Er3+ complexes. In the crystal, the complex cations are linked by pairs of O-H⋯O hydrogen bonds into dimers. These dimers, nitrate anions and non-coordinating water mol-ecules are joined by O-H⋯O and N-H⋯O hydrogen bonds into a three-dimensional structure.

Synthesis and Structural Studies of Cp* Rhodium and Cp* Iridium Complexes of Picolinic Hydrazine Ligand

A series of Cp*Rh and Cp*Ir complexes of picolinic hydrazine ligand are synthesized and characterized. Picolinic hydrazine has yielded only dinuclear complexes in the case of rhodium metal whereas both mono and dinuclear complexes with iridium metal. Iridium complexes are formed as quaternary salts by the migration of the N–H proton onto the adjacent amine group of the hydrazine after binding to the metal. Picolinic hydrazine acts as nitrogen and oxygen donor ligand in the form of bi and tetradentate bonding modes.

Aluminum and Gallium Hydrazides as Active Lewis Pairs: Cooperative C–H Bond Activation with H–C≡C–Ph and Pentafluorobenzene

Hydroalumination or hydrogallation of a sterically encumbered hydrazone, H10C5N–N═C(C9H14) (NC5H10 = piperidine, C(C9H14) = 2-adamantdiyl), afforded hydrazides that, depending on the steric shielding by the substituents at the metal atoms, had different molecular structures. While both di(tert-butyl)metal derivatives (1a, 1b) are monomeric in the solid state with highly strained MN2 heterocycles (M = Al, Ga), the dimethylmetal compounds (1c, 1d) are dimeric with M2N2 heterocycles and exocyclic N–N bonds. The latter compounds are highly dynamic in solution. 1d crystallized as a mixture of cis- and trans-isomers as detected by crystal structure determinations. These compounds react as active Lewis pairs by their specific donor–acceptor functionality and are able to activate C–H bonds of moderately acidic substrates. Reaction of 1a (M = Al) with H–C≡C–C6H5 afforded by C–H bond activation and release of H–CMe3 trialkynyl compound 4, in which three alkynyl groups and a neutral hydrazine ligand are bound to Al....

Solvent-controlled synthesis and reversible dynamic structural conversions of a series of iron(II) coordination complexes

In this work, a versatile multi-dentate 1,2-bis(pyridin-4-ylmethylene)hydrazine (L) ligand has been employed to construct three novel iron(II) coordination complexes, [Fe(L)2(NCS)2(H2O)2]·2H2O (1), [Fe(L)(NCS)2(H2O)2] (2) and {[Fe(L)2(NCS)2]·2CH3OH}n (3) (NH4NCS=ammonium thiocyanate), which can be isolated under similar synthetic conditions, only different molar ratio of metal/ligand or different solvent systems are used. 1 is a mono-nuclear iron(II) coordination complex, and 2 is a one-dimensional (1D) iron(II) coordination complex, while 3 is a 2D micro-porous iron(II) framework with the channel dimensionality of 13.936(3) Å×13.936(3) Å. PXRD patterns also confirm the purity of the bulky samples of 1–3. For 1–3, it represents the first example of solvent-induced drastic reversible dynamic conformation between different dimensional iron(II) coordination complexes 1 (0D), 2 (1D) and 3 (2D) (for 1: water; for 2: benzene; for 3: methanol/acetone/acetonitrile), which are unambiguously confirmed by PXRD characterizations. Variable-temperature magnetic susceptibility data of 2–3 have been recorded in the 2–300K temperature range, indicating weak antiferromagnetic interactions.

A general method for preparing lanthanide oxide nanoparticles via thermal decomposition of lanthanide(III) complexes with 1-hydroxy-2-naphthoic acid and hydrazine ligands

Six new lanthanide(III) complexes (i.e., [Ln(L)2(NA)1.5]·3H2O, where Ln=La(III), Pr(III), Nd(III), Sm(III), Gd(III), and Ce(III) and L and NA indicate N2H4 and C10H6(1-O)(2-COO), respectively) with 1-hydroxy-2-naphthoic acid [C10H6(1-O)(2-COOH)] and hydrazine (N2H4) as co-ligands were characterized by elemental, FTIR, UV-visible, and XRD techniques. In the FT-IR spectra, the N-N stretching frequency in the range of 981–949cm−1 demonstrates evidence of the presence of coordinated N2H4, indicating the bidentate bridging nature of hydrazine in the complexes. These complexes show symmetric and asymmetric COO− stretching from 1444 to 1441cm−1 and 1582 to 1557cm−1, respectively, indicating bidentate coordination. TG-DTA studies revealed that the compounds underwent endothermic dehydration from 98 to 110°C. This was followed by the exothermic decomposition of oxalate intermediates to yield the respective metal oxides as the end products. From SEM images, the average size of the metal oxide particles prepared by thermal decomposition of the complexes was determined to be 39–42nm. The powder X-ray and SEM coupled with energy dispersive X-ray (EDX) studies revealed the presence of the respective nano-sized metal oxides. The kinetic parameters of the decomposition of the complexes were calculated using the Coats-Redfern equation.

Crystal structure of hydrazine iron(III) phosphate, the first transition metal phosphate containing hydrazine.

The title compound, poly[(μ2-hydrazine)(μ4-phosphato)iron(III)], [Fe(PO4)(N2H4)] n , was prepared under hydro-thermal conditions. Its asymmetric unit contains one Fe(III) atom located on an inversion centre, one P atom located on a twofold rotation axis, and two O, one N and two H atoms located on general positions. The Fe(III) atom is bound to four O atoms of symmetry-related PO4 tetra-hedra and to two N atoms of two symmetry-related hydrazine ligands, resulting in a slightly distorted FeO4N2 octa-hedron. The crystal structure consists of a three-dimensional hydrazine/iron phoshate framework whereby each PO4 tetra-hedron bridges four Fe(III) atoms and each hydrazine ligand bridges two Fe(III) atoms. The H atoms of the hydrazine ligands are also involved in moderate N-H⋯O hydrogen bonding with phosphate O atoms. The crystal structure is isotypic with the sulfates [Co(SO4)(N2H4)] and [Mn(SO4)(N2H4)].