3D Solid-State Network from Hierarchical Supramolecular Self-Assembly of Transition Metal Complexes of Pyridine Based Ligand

Abstract  The crystal structures of [Cu(py)₄(ClO₄)](ClO₄) (1), [V(pic)₂(OH)](NO₃)₂ · H₂O (2) and [Ni(H₂O)₆][Ni(dpa)₂] · 2H₂O (3) [py = Pyridine, picH = Pyridine-2-carboxylic acid, dpaH₂ = Pyridine-2,6-dicarboxylic acid] was determined by single-crystal X-ray diffraction techniques. Solid-state structural analysis shows that all these complexes from extensive 3D network structure via supramolecular self-assembly. The crystal structures are stabilized by extended hydrogen bonding interactions. The complex 2 forms orange V₂O₅ micro spheroids when heated at ~400 °C for 6 h. Graphical Abstract  Hierarchical supramolecular self-assembly of transition metal complexes of pyridine based ligands in crystal. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

CoL(SO4)0.5 ?·?4H2O and MnL2 ?· 2H2O (L = 1,10-Phenanthroline-4,5- f -triazolate): Synthesis, Crystal Structures and Hydrogen-Bonded Networks

Abstract  Two metal complexes of 1H-triazo-4,5-f-1,10-phenanthroline (HL), CoL(SO₄)_0.5 · 4H₂O (1) and MnL ₂ · 2H₂O (2) have been synthesized on hydrothermal conditions and characterized by elemental analysis, IR spectroscopy and single-crystal X-ray diffraction analysis. Complex 1 was further assembled into a three-dimensional (3D) supramolecular network through the hydrogen-bonding interactions and inter-molecular π···π stacking interaction, 2 further assembled into a two-dimensional (2D) layer structure. This result shows that hydrogen-bonding interactions and π···π stacking interaction play important roles in the formation of coordination networks, especially in the aspect of linking the multinuclear discrete subunits or low-dimensional entities into high-dimensional supramolecular frameworks. Index abstract  Two metal complexes of 1H-triazo-4,5-f-1,10-phenanthroline (HL), CoL(SO₄)_0.5 · 4H₂O (1) and MnL₂ · 2H₂O (2) have been synthesized on hydrothermal conditions. Complex 1 was further assembled into a three-dimensional (3D) supramolecular network through the hydrogen-bonding interactions and inter-molecular π···π stacking interaction, 2 further assembled into a two-dimensional (2D) layer structure.      

Synthesis and Crystal Structure of a Polymorph of the DMF Solvate of the Dicoppertetracarboxylate Paddlewheel Complex Cu<Subscript>2</Subscript>(p-aminobenzoate)<Subscript>4</Subscript>(DMF)<Subscript>2</Subscript>

Abstract  Reaction between p-aminobenzoic acid (HpABA) and Cu(NO₃)₂ · 2.5H₂O in basic MeOH/DMF affords green crystals of the dicopper paddlewheel complex, Cu₂(pABA)₄(DMF)₂ · 2DMF, 1, identified by single crystal X-ray crystallography: triclinic P-1, with a = 10.3728(2) ?, b = 10.617(2) ?, c = 11.128(2) ?, α = 81.705(3)°, β = 79.984(2)°, γ = 65.965(2)° and Z = 2. The crystal structure of 1 reveals that it is the second polymorph of Cu₂(pABA)₄(DMF)₂ · 2DMF and experiments on the stability of 1 indicate that it can be converted to Form I through desolvation followed by exposure to DMF. Graphical Abstract  Crystal structure of a polymorphic discrete dicoppertetracarboxylate is investigated for the conversion between the two forms influenced by hydrogen bonds.      

C–H···F Hydrogen-Bonded Assembly of Ni(II) and Cu(II) Complexes Generate 3D Supramolecular Frameworks

Abstract  Syntheses and X-ray structural characterizations of two new complexes [Ni(imi)₆](pfbz)₂ (1) and Cu(imi)₂(pfbz)₂ (2) (imi = imidazole, pfbz = pentafluorobenzoate) are reported. The first complex crystallizes in the triclinic space group P-1 with the crystal cell parameters a = 9.180(2) ?, b = 9.742(3) ?, c = 11.466(3) ?, α = 76.947(18)°, β = 80.629(18)°, γ = 78.043(19)°, V = 970.0(4) ?³ and Z = 1. The second complex crystallizes in the triclinic space group P-1 with the crystal cell parameters a = 7.3250(12) ?, b = 7.6685(10) ?, c = 10.888(4) ?, α = 92.80(2)°, β = 101.92(2)°, γ = 115.038(12)°, V = 535.7(2) ?³ and Z = 1. Examination of the structures shows that both complexes form three-dimensional hydrogen bonded networks in which C–H···F hydrogen bonds play significant roles. Index Abstract   C–H···F Hydrogen-Bonded Assembly of Ni(II) and Cu(II) Complexes Generate 3D Supramolecular Frameworks Chun-Hua Ge, Xiao-Yan Zhang, Fang Yu, Ya-Nan Guo, Xiang-Dong Zhang* and Qi-Tao Liu C–H···F interactions link simple complexes to form intricate three-dimensional supramolecular networks.      

Syntheses,Crystal Structures and Fluorescence Properties of Zn(II) Complexes with Pyrazolone Derivatives

Abstract   N-(1,3-Diphenyl-4-benzal-5-pyrazolone)-salicylidene hydrazone(H₂L ¹ ) and its zinc complex Zn(HL ¹ )₂ · 2CH₃OH (1) have been synthesized and characterized by elemental analyses, IR spectra, thermal analyses and single-crystal X-ray diffraction studies. The X-ray diffraction analyses of the complex Zn(HL ¹ )₂ · 2CH₃OH (1) and the known compound Zn₄(L ² )₄ (2) (H₂L ²  = N-(1,3-diphenyl-4-phenylethylene-5-pyrazolone)-salicylidene hydrazone) show that different acyl groups in position 4 of pyrazolones may lead to the different coordination mode of the ligands and distinctive structures of the same central metal Zn(II) complexes, of which 1 is a mononuclear complex while 2 is a tetranuclear complex. Meanwhile, two Zn(II) complexes have different thermal stabilities and fluorescence properties. Graphical Abstract        

Synthesis and Crystal Structure of a Novel Double-Chain Coordination Polymer [Zn<Subscript>2</Subscript>(bipy)<Subscript>2</Subscript>(btec)(H<Subscript>2</Subscript>O)<Subscript>2</Subscript>]<Subscript>n</Subscript> (bipy = 2,2′-bipyridine; btec = 1,2,4,5-benzenetetracarboxylate)

Abstract  A novel aromatic polycarboxylate polymer, [Zn₂(bipy)₂(btec)(H₂O)₂]_n (1), has been synthesized and structurally characterized by the single crystal X-ray diffraction. Compound 1 belongs to the triclinic crystal system, space group P-1; a = 7.7449(6) ?, b = 8.9286(8) ?, c = 10.7422(8) ?, α = 80.95(1)°, β = 70.21(1)°, γ = 78.14(1)°, V = 680.93(10) ?³, Z = 2. The coordination geometry of Zn(II) atom is distorted trigonal bipyramidal with two nitrogen atoms of one 2,2′-bipy group, two oxygen atoms from two different btec ligands, and one water. The 16-membered rings are alternately arranged forming an infinite 1-D double-chain structure. A 3-D network was constructed by interlayer C···H–O, O···H–O hydrogen bonds and π–π stacking interactions. Compound 1 exhibits fluorescence at room temperature in the solid state. Graphical Abstract  A 1-D double-chain aromatic polycarboxylate polymer, [Zn₂(bipy)₂(btec)(H₂O)₂]_n (1), has been synthesized and structurally characterized by the single crystal X-ray diffraction. A 3-D network was constructed by intermolecular C···H–O, O···H–O hydrogen bonds and π–π stacking interactions. Compound 1 exhibits fluorescence at room temperature in the solid state.      

Synthesis and Crystal Structures of Two Metal Urea Nitrates

Abstract  Cu(urea)₂(H₂O)₃(NO₃).(urea)(NO₃) (1) and Zn(urea)₄(H₂O)₂·2(NO₃) (2) have been obtained from the corresponding metal nitrates and urea in warm aqueous solvent. These are unusual examples of complexes of transition metals coordinated only by urea and water. 1 crystallizes in the monoclinic space group P2₁/m with unit cell parameters a = 9.489(3), b = 13.059(3), c = 7.103(2) ? and β = 100.28(3)°. The copper ion occupies a 2e position on a mirror plane and displays four short Cu–O bonds (2 × Cu–OH₂ and 2 × Cu–O=C(NH₂)₂) and two much longer contacts (Cu–OH₂ and Cu–ONO₂) consistent with a Jahn–Teller distortion. Between the cations are located unbound urea and nitrate. 2 crystallizes in the monoclinic space group P2₁/n with a = 6.4239(11), b = 17.690(4), c = 7.5877(13) ? and β = 91.138(14)°. The zinc ion resides on the 2a position, an inversion centre, and displays pseudo–octahedral coordination geometry. It is coordinated by four equatorial urea and two axial water molecules. The four molecules of urea are nearly planar and form N–H···O intramolecular hydrogen bonds. Unbound charge-balancing nitrate is also present. In each compound there is extensive intermolecular hydrogen bonding between the water, urea, and nitrate present. Pyrolysis of the compounds under 10% hydrogen in nitrogen at 300 °C was found to yield metallic copper in the case of 1 and zinc oxide for 2. Graphical Abstract  The structures of two new metal urea nitrates have been determined at low temperature      

Isostructural Series of (2,2′-Bipyridinium)tetrabromometallate(II); Intermolecular Interactions in the Structures of (bpyH<Subscript>2</Subscript>)[MBr<Subscript>4</Subscript>]; M = Zn,Hg and Co

Abstract  A single crystal structure determination of the complexes (2,2′-bipyridinium)[MBr₄], M = Zn, Hg and Co, have been carried out. It crystallizes in the monoclinic space group P2₁ /c. The structures consist of alternating stacks of anions and cations. They demonstrate a supramolecularity represented by the inter anion···cation, N–H···Br and C–H···Br interactions. The N–H···Br hydrogen bonding interactions, ca. 3.306(3)–3.213(7) ? and with angles spanning the range 154–156°, tying the MBr₄ anions to the cations. Intra- and interstack anion···anion interactions represented by Br···Br interactions, also exist. All these interactions lead to a 3D-network. Index Abstract        

Synthesis and Crystal Structure of a Mixed-Ligand Cobalt(II) Complex with 2-Aminobenzimidazole

Abstract  The cobalt(II) complex, [Co(abz)₂(SCN)₂] 1, has been synthesized by the reaction of cobalt(II) nitrate with ammonium thiocyanate and abz ligands (abz = 2-aminobenzimidazole), and was fully structurally characterized by elemental analysis, IR spectra, X-ray diffraction and thermogravimetric experiments. It crystallizes in the triclinic P-1 space group with a = 8.6316(10), b = 9.3426(10), c = 13.254(2) ?, α = 95.793(2), β = 95.870(2), γ = 115.7380(10), V = 945.1(2) ?³, and Z = 2. The central cobalt(II) atom is four-coordinated to nitrogen donors from two neutral abz ligands and two isothiocyanate anions respectively, adopting a slightly distorted tetrahedral geometry. In addition, the intermolecular N–H···N and N–H···S hydrogen bonds interactions link the discrete mononuclear units into infinite three-dimensional networks. Index Abstract  The essence sentence of the paper: In the mixed-ligand mononuclear complex, [Co(abz)₂(SCN)₂], the four coordinated cobalt(II) atom exhibits a slightly distort tetrahedron, which is further assembled into 3D infinite network by intermolecular hydrogen interactions.      

Synthesis and Crystal Structure Analysis of Thiourea-Pendant Pyridines

Abstract  The crystal structures of pyridine containing thiourea moieties as substituents, (1) and (2), have been determined. The ortho-substituted pyridine (1) crystallized in monoclinic space group P2₁/c with a = 16.091(3) ?, b = 11.368(2) ?, c = 7.4364(14) ?, β = 100.489(4)o, V = 1337.5(4) ?³, z = 4. In this structure an intramolecular N–H···N hydrogen bond forms a pseudo-seven-membered ring. The meta-substituted pyridine (2) crystallized in monoclinic space group P2₁/c with a = 14.5408(15) ?, b = 8.8508(9) ?, c = 10.7959(11) ?, β = 106.435(2)o, V = 1332.6(2) ?³, z = 4. Crystal packing revealed that compounds (1) and (2) can form dimeric structures via intermolecular H-bonding using N–H···S and N–H···N interactions, respectively. Graphical Abstract  Varying the substituent position on the pyridine ring using thiourea moieties gave unique molecular aggregations in solid state structures.      

Molecular Structure of [Cu<Subscript>2</Subscript>(MeCN)<Subscript>2</Subscript>(μ-tpy)<Subscript>2</Subscript>][BPh<Subscript>4</Subscript>]<Subscript>2</Subscript>: A Helical Di-Cuprous Terpyridine Complex

Abstract  The molecular structure of [Cu₂(MeCN)₂(μ-tpy)₂][BPh₄]₂ has been determined. The two terpyridine ligands coordinate to the same Cu(I) center in a bidentate configuration, in which the copper adopted a distorted tetrahedral geometry with the four nitrogen donors. The third ring of each terpyridine ligand forms a bridge with a second Cu(I) center, whose tetrahedral coordination sphere is completed by two acetonitrile ligands. The resulting structure represents a section of a double helix. Crystal data: space group C2/c, a = 27.202(5), b = 12.995(3), c = 23.409(5) ?, β = 123.13(3)°; V = 6930(2) ?³, Z = 4, R = 0.0613, wR ₂ = 0.0946. Graphical Abstract  The molecular structure of [Cu₂(MeCN)₂(μ-tpy)₂][BPh₄]₂ has been determined. The terpyridine ligands coordinate in a bidentate fashion to the same Cu center and monodentate to a second Cu center resulting in a double helical structural motif.      

Solvothermal Synthesis and Crystal Structure of a 18-Membered Macrocycle Schiff Base Dinuclear Copper(II) Complex: Cu2(NO3)4(APTY)4 (APTY = 1,5-dimethyl-2-phenyl-4-{[(1E)-pyridine-4-ylmethylene]amino}-1,2-dihydro-3H-pyrazol-3-one)

Abstract  A new 18-membered macrocycle Schiff base dinuclear copper(II) complex: Cu₂(NO₃)₄(APTY)₄ (1) (APTY = 1,5-dimethyl-2-phenyl-4-{[(1E)-pyridine-4-ylmethylene]amino}-1,2-dihydro-3H-pyrazol-3-one), has been successfully synthesized by solvothermal treatment of Cu(NO₃)₂ · 6H₂O with APTY. Compound 1 crystallizes in the triclinic space group P-1 with cell parameters: a = 10.556(2) ?, b = 12.075(2) ?, c = 15.230(3) ?, α = 74.75(3), β = 81.50(3), γ = 70.60(3)°, V = 1762.7(6) ?³, R1 = 0.0493, wR2 = 0.1400, Z = 1, D _calc = 1.455 g/cm³, F(000) = 798, S = 1.009. In the compound molecules, each of the six-coordinated Cu^II atoms are bridged by APTY ligands into 18-membered macrocycle, and each the Cu²⁺ atoms exhibits a significantly distorted octahedral geometry. The crystal packing is stabilized by C–H···O hydrogen-bonding interactions into a three-dimensional supramolecular framework. Index Abstract  A new 18-membered macrocycle Schiff base dinuclear copper(II) complex: Cu₂(NO₃)₄(APTY)₄ (1), has been successfully synthesized by solvothermal treatment (APTY = 1,5-dimethyl-2-phenyl-4-{[(1E)-pyridine-4-ylmethylene]amino}-1,2-dihydro-3H-pyrazol-3-one). The six-coordinated Cu²⁺ atom exhibit significantly distorted octahedral geometry. The crystal packing is stabilized by C–H···O hydrogen-bonding interactions into a three-dimensional supramolecular framework.     

Structures of Bis(1-ethylbenzimidazol-2-yl)alkyl Copper(II) Dichlorides: An Unusual Cocrystallization

Abstract  Two structures containing pseudo-tetrahedral Cu(II)N₂Cl₂ coordination complexes are reported. The first molecular structure (A) of the compound, 1,1′bis(1-ethylbenzimidazol-2-yl)propane copper(II) dichloride (triEtBBIM)Cu(II)Cl₂, 1, is reported. The complex crystallized in the triclinic space group P-1 with a = 8.616(3) ?, b = 9.302(3) ?, c = 14.314(4) ?, α = 85.613(6)°, β = 85.170(6)°, γ = 66.117(6)° and V = 1044.1(5) ?³ with Z = 2. The second structure (B) contains 1 and (3,3′bis(1-ethylbenzimidazol-2-yl)pentane) copper(II) dichloride (tetEtBBIM)Cu(II)Cl₂, 2, both of which, cocrystallize in an equal molar ratio with a nitromethane solvate molecule. The complex crystallized in the monoclinic space group P2₁/c with a = 18.876(4) ?, b = 14.975(3) ?, c = 18.344(4) ?, β = 116.75(3)°, and V = 4630.3(16) ?³ with Z = 4. The cocrystallization of such discrete complexes has been coined a chemical Janus. Graphical Abstract  The title complexes contain pseudo-tetrahedral Cu(II)N₂Cl₂ coordination. One of the structures is the result of an unusual cocrystallization, in which two different discrete Cu(II) molecules cocrystallize in an equimolar ratio with a nitromethane solvate molecule.      

Kinetics of Desolvation and Structure of Bulky Xanthenol Inclusion Compounds

Abstract  The inclusion compounds of 14-hydroxy-14-toluenyldibenzo[a:j]xanthene (H) with the guests acetone (H·ACE), pyridine (H·PYR) and N,N-dimethylformamide (H·DMF) were all successfully solved in the triclinic spacegroup P-1 with unit cell dimensions for H·ACE: a = 9.415(2) ?, b = 9.730(2) ?, c = 12.994(3) ?, α = 82.65(3), β = 76.69(3), γ = 88.67(3), Z = 2; for H·PYR: a = 9.482(2) ?, b = 10.169(2) ?, c = 13.089(3) ?, α = 106.59(3), β = 95.91(3), γ = 90.35(3), Z = 2 and for H·DMF: a = 9.537(19) ?, b = 10.055(2) ?, c = 13.129(3) ?, α = 79.18(3), β = 74.42(3), γ = 86.46(3), Z = 2. The thermal stabilities for all compounds were investigated and in particular the kinetics of desolvation for the DMF compound was determined using both isothermal and non-isothermal methods. Index Abstract  The host compound 14-hydroxy-14-toluenyldibenzo[a:j]xanthene forms inclusion compounds with the guests acetone, pyridine and N,N-dimethylformamide. The crystal structures were determined and their thermal stabilities investigated. The kinetics of desolvation for the DMF compound was determined using both isothermal and non-isothermal methods.      

Synthesis and Crystal Structure of a New Binuclear Samarium Complex with Salicylate

Index Abstract  In the dinuclear compound (HPhen)₂[Sm₂(Hsal)₈(H₂O)₂] · 2H₂O (Hsal = o-HOC₆H₄CO₂ ⁻, Phen = 1,10-phenanthroline), intermolecular hydrogen bonds and π–π stacking interactions between parallel aromatic rings result in the formation of a two-dimensional supramolecular network.      

Crystal Structure and Magnetic Properties of a Novel Octa-coordinated Manganese(II) Complex

Abstract  The self-assembly and structural characterization of the new manganese(II) [MnL ₂](ClO₄)₂(CH₃OH)_0.5 (1) complex has been achieved. The crystallographic data for the complex 1: Orthorhombic Pbca , a = 16.287(2) ?, b = 21.293(2)?, c = 32.718(3) ?, V = 11,347(2) ?³, Z = 8. The two polydentate ligands strand intertwined each other and around the manganese(II) ions forming a mononuclear complex. The Mn(II) ion is eight-coordinated with the eight donor nitrogen atoms of two ligands to form a distorted square antiprismatic coordination geometry. The magnetic properties investigation indicates that there is a weak antiferromagnetic exchange coupling between the Mn(II) ions of the complex. Index Abstract  An octa-coordinated Mn(II) complex which exhibits a distorted square antiprismatic coordination geometry has been achieved by using a bisbidentate Schiff-base ligand.      

Synthesis and Characterization of [(1-benzylpyrazole) [<Emphasis Type="Italic">N</Emphasis>,<Emphasis Type="Italic">N</Emphasis>-bis(2-aminoethyl)-1,2-ethanediamine]copper(II)] Diperchlorate,a Structure with a Sterically Strained,Distorted-Trigonal-Bipyramidal Cation

Abstract  The synthesis, characterization, and molecular structure of the title compound, [(1-benzylpyrazole)[N,N-bis(2-aminoethyl)-1,2-ethanediamine]copper(II)] diperchlorate, [(nbp)(tren)Cu(II)](ClO₄)₂, 2  · 2ClO₄, is reported. The salt crystallized in the monoclinic space group P2₁/n with a = 10.1453(5) ?, b = 17.5250(8) ?, c = 13.6021(6) ?, β = 100.737(19)° and V = 2376.06(19) ?³ with Z = 4. The structure contains copper(II) (nbp)(tren) cations, each with a distorted-trigonal-bipyramidal CuN₅ coordination geometry, separated by perchlorate anions. The cations exhibit steric strain associated primarily with close contacts between the methylene protons of the nbp ligand and one of the amine groups of the tren ligand. The strain has a noticeable effect on the coordination geometry and certain physical properties of the complex. Graphical Abstract  In the title structure, steric strain in the (nbp)(tren)Cu(II) cations, associated with close contacts between protons of the nbp ligand and two of the amine groups of the tren ligand (dashed lines in the figure below) affects certain physical properties of the cation and is consistent with an anomalously long Cu(II)–N(pyrazole) distance (Cu–N41) and an unusually large axial–equatorial angle, N41–Cu–N12.      

Hydrogen-bonded Multicomponent Behavior in Tetra-<Emphasis Type="Italic">iso</Emphasis>-butyl-resorcin[4]arene–1,4-Bis(pyridyl)ethane–Methanol–Water (1/2/0.5/1)

Abstract  Co-crystallization of the tetra-iso-butyl-resorcin[4]arene (1) with 1,4-bis-(pyridyl)ethane (bpe) obtained from methanol yields a molecular solid of the multicomponent host–guest complex 1 · 2(bpe) · 0.5MeOH · H₂O (2) in which 1 assemblies with water molecules to form a hydrogen-bonded dimer. The bpe ligands in both cis- and trans-stereo configurations exist in the complex 2, of which trans-bpe moieties as guests are encapsulated in the capsules constructed by two pairs of opposition bowls of resorcinarenes. Graphical Abstract  The 1,4-bis(pyridyl)ethane (bpe) ligands in both cis- and trans-stereo configurations exist in a multicomponent molecular solid, of which trans-bpe moieties as guests are encapsulated in the capsules constructed by two pairs of opposition bowls of resorcinarenes.      

Hydrothermal Synthesis,Crystal Structure,and Luminescence Property of Two Lanthanide Coordination Polymers with Diglycolic Acid

Abstract  Two new coordination polymers {[Tb₂(C₄H₄O₅)₃ · 4H₂O] · 2H₂O} _n (1) and {[La₂(C₄H₄O₅)₃ · 3H₂O] · 3H₂O} _n (2) (C₄H₄O₅ ²⁻ = diglycolato) were prepared by hydrothermal reaction and characterized by X-ray crystallography. The two complexes have different network structures through carboxylate oxygen atoms and ether oxygen atoms from diglycolato ligands linking lanthanide ions. The characteristic transition bands ⁵D₄ → ⁷F_J (J = 6 − 3) of Tb(III) ion are observed in complex 1. Graphical Abstract  Two new coordination polymers {[Tb₂(C₄H₄O₅)₃ · 4H₂O] · 2H₂O} _n (1) and {[La₂(C₄H₄O₅)₃ · 3H₂O] · 3H₂O} _n (2) (C₄H₄O₅ ²⁻ = diglycolato) have network structures through the carboxylate oxygen atoms and ether oxygen atoms from diglycolato ligands. The emission spectrum of complex 1 indicates the ⁵D₄ → ⁷F_J (J = 6 − 3) transitions of Tb(III) ion.      

The Synthesis and Crystal Structure of 5-Methyl-1-(1-naphthyl)-1,2,3-triazol-4-carboxyl Acid

Abstract  5-Methyl-1-(1-naphthyl)-1,2,3-triazol-4-carboxyl acid 3 was synthesized from 1-aminonaphthalene. The yielded product 3 was investigated with X-ray crystallographic, NMR, MS and IR techniques. Compound 3, C₁₄H₁₁N₃O₂, Mr = 253.26, crystallizes in the orthorhombic space group Pbca with unit cell parameters a = 10.068(2), b = 12.353(2), c = 20.102(4) ?, V = 2500.1(8) ?³, Z = 8, Dx = 1.346 Mgm^-3. The final R was 0.0474. The molecular packing is stabilized by intermolecular O–H···N interactions. Index Abstract  5-Methyl-1-(1-naphthyl)-1,2,3-triazol-4-carboxyl acid 3 was synthesized from 1-aminonaphthalene. The yielded product 3 was investigated with X-ray crystallographic, NMR, MS and IR techniques. Compound 3, C₁₄H₁₁N₃O₂, Mr = 253.26, crystallizes in the orthorhombic space group Pbca with unit cell parameters a = 10.068(2), b = 12.353(2), c = 20.102(4) ?, α = β = γ = 90.00o. V = 2,500.1(8) ?³, Z = 8, Dx = 1.346 Mgm⁻³. The final R was 0.0474. The molecular packing is stabilized by intermolecular O–H···N interactions.