Azide Bridges Research Articles

Chinese-Lantern shaped [MnII2MnIII6NaI3] cluster assembled from Schiff base and azide bridges: Synthesis, magnetic study and catecholase-like activity

A multisite Schiff base, H2damp, derived from the condensation of o-vanillin and a sterically constrained amino-alcohol (2-amino-2-methylpropan-1-ol) was utilized to isolate a new mixed valence heterometallic complex [Na3MnIII6MnII2(damp)6(µ4-O)2(µ1,3-O2CCH3)2(µ1,1-N3)6(µ1,1,3-N3)(H2O)2]·5H2O·CH3OH (1). Room temperature reaction of H2damp in MeOH with Mn(II) acetate and NaN3 provided the complex having MnII2MnIII6NaI3 core. X-ray structure determination revealed the use of azide ancillary ligands for the growth of the complex on ligand-bound MnIII3O fragments. The variable temperature magnetic characterization of 1 revealed intramolecular anti-ferromagnetic exchange interactions. Complex 1 also showed catalytic property for the aerial oxidation of 3,5-di-tert-butyl catechol (3,5-DTBCH2) with a turnover number (kcat) of 392 h−1. EPR and mass spectrometric analysis established the probable mechanism of catalytic oxidase reactivity on the model substrate. In EPR study the characteristic peak at g ∼ 2 allowed us to spot the presence of an organic radical confirming the conversion of DTBCH2 to DTBQ in radical pathway.

Binuclear azide-bridged hydrazone Cu(II) complex: Synthesis, characterization and evaluation of biological activity

The condensation product of 7-acetyl-6-azaindole and Girard?s T reagent ((E)-2-(2-(1-(1H-pyrrolo[2,3-c]pyridin-7-yl)ethylidene)hydrazineyl)- -N,N,N-trimethyl-2-oxoethan-1-aminium, HL ligand) was used as a ligand in the reaction with Cu(BF4)2?6H2O and NaN3. The reaction led to the formation of a binuclear Cu(II) complex containing two end-to-end (di-?-1,3-N3) azide bridges, as well as two NNO-donor hydrazone ligands, forming an axially elongated square pyramidal geometry around each Cu(II) center. This end-to-end (di- ?-1,3-N3) azide bridge binding mode has not yet been reported, in Cu(II) complexes containing the NNO-donor hydrazone ligands, which makes the structure of the complex even more interesting for further studies. The complex was characterized by elemental analysis, IR spectroscopy and X-ray crystallography, and it was found that it crystallizes in the triclinic space group P?1 with the asymmetric unit comprising one Cu(II) centre, zwitterionic ligand L, one azide (N3 -) ligand and BF4 - counter anion. Examination of antimicrobial activity of the complex shows higher antifungal and antibacterial activity towards tested Gram-positive bacteria in comparison to the hydrazone ligand, with the antifungal activity of the complex even being comparable to the activity of amphotericin B.

Water oxidation reaction in the presence of a dinuclear Mn(II)-semicarbohydrazone coordination compound.

Water splitting, producing of oxygen, and hydrogen molecules, is an essential reaction for clean energy resources and is one of the challenging reactions for artificial photosynthesis. The Mn4Ca cluster in photosystem II (PS-II) is responsible for water oxidation in natural photosynthesis. Due to this, water oxidation reaction by Mn coordination compounds is vital for mimicking the active core of the oxygen-evolving complex in PS-II. Here, a new dinuclear Mn(II)-semicarbohydrazone coordination compound, [Mn(HL)(µ-N3)Cl]2 (1), was synthesized and characterized by various methods. The structure of compound 1 was determined by single crystal X-ray analysis, which revealed the Mn(II) ions have distorted octahedral geometry as (MnN4OCl). This geometry is created by coordinating of oxygen and two nitrogen donor atoms from semicarbohydrazone ligand, two nitrogen atoms from azide bridges, and chloride anion. Compound 1 was used as a catalyst for electrochemical water oxidation, and the surface of the electrode after the reaction was investigated by scanning electron microscopy, energy dispersive spectrometry, and powder X-ray diffraction analyses. Linear sweep voltammetry (LSV) experiments revealed that the electrode containing 1 shows high activity for chemical water oxidation with an electrochemical overpotential as low as 377mV. Although our findings showed that the carbon paste electrode in the presence of 1 is an efficient electrode for water oxidation, it could not withstand water oxidation catalysis under bulk electrolysis and finally converted to Mn oxide nanoparticles which were active for water oxidation along with compound 1.

Concomitant dimorphism in poly[di-μ-azido-(5,5'-dimethyl-2,2'-bipyridine)iron(II)

The title metal-organic polymer, catena-poly[[(5,5'-dimethyl-2,2'-bipyridine-κ2N,N')iron(II)]-di-μ-azido-κ2N1:N3-[(5,5'-dimethyl-2,2'-bipyridine-κ2N,N')iron(II)]-di-μ-azido-κ2N1:N1], [Fe(N3)2(C12H12N2)]n, features alternating μ-1,1 (end-on mode of coordination) and μ-1,3 (end-to-end mode of coordination) double azide bridges, forming chains running in the [100] direction. The octahedral coordination geometry around the FeII centre is completed by a bidentate 5,5'-dimethyl-2,2'-bipyridine ligand. Two polymorphs for this compound were obtained from the crude reaction product, the first in the space group P-1 and the other in P21/c. The molecular and crystal structures are very similar for both forms, the main difference being that the eight-membered Fe(μ-1,3-N3)2Fe metallacycle formed with end-to-end azide ligands has a nearly flat conformation in the triclinic form and a chair conformation in the monoclinic form. In spite of this geometric difference, both forms have the same density, the same packing index and similar arrangements of the one-dimensional chains in the crystal. As a consequence, they also share very similar Hirshfeld surfaces and fingerprint plots. However, a density functional theory (DFT) computational study showed that the monoclinic form is more stable than the triclinic form by ca 30.5 kJ mol-1.

Vibrational spectra, force constants and quantum chemical calculations of μ-1,3-azide bridged triphenylphosphine complexes of copper(I) and silver(I)

The dimeric title compounds [(C6H5)3P]Cu2(N3)2 and [C6H5)3P]Ag2(N3)2 were synthesized and characterized by FT-Raman and IR spectroscopy. The two phases were not isotypic but possessed approximately the same molecular symmetry which was C2/2m. The assignment of the modes was supported by quantum chemical DFT calculations coupled with TED (Total Energy Distribution) analyses. The calculated (NN) force constants for the bridging --(NNN)-- groups were directly comparable (f(NN) = 11.75 (Cu) and 12.19 N cm−1(Ag)) and harmonized well with those of the free azide anion in the binary alkali azides. The (NN) bond orders were obtained based on the calculated force constants (Siebert Bond Order, SBO) and Density-dependent electrostatic and chemical (DDEC6) method yielding SBO = 1.92 (Cu) and 1.96 (Ag) and BO = 2.00 (Cu) and 2.03 (Ag), respectively, indicating the presence of double bonds. The results underlined that the (NN) force constants and bond orders in the bridging azide units were practically unaffected by the nature of the central metal atoms and that they could be regarded as quasi isolated anions similar to those in the binary azide compounds.

The mechanism of phase transitions and luminescence properties of azide perovskites

The temperature-dependent IR and Raman spectroscopy has been used to study the phase transitions in Na/K-chromium-azide frameworks with tetramethylammonium (TeMA+) cations, [(CH3)4N]2[NaCr(N3)6] and [(CH3)4N]2[KCr(N3)6], which crystallize in a perovskite-like structure. The phase transition occurring within 310–315 K in both compounds leads to a symmetry change from Pa-3 to Fm-3m and its major contributor is an order-disorder process of the organic cations followed by an adjustment of the azide bridges. The luminescence properties arise from the optically active Cr3+ ions and the studies reveal some admixture of low-symmetry component of the octahedral crystal environment of the Cr3+ sites.

Magnetically coupled iron azide chains

Three well-defined iron(II) compounds CztBu(PyriPr)2FeCl (1), CztBu(PyriPr)2FeCl(THF) (2), and CztBu(PyriPr)2FeN3 (3), supported by the NNN pincer ligand CztBu(PyriPr)2− were synthesized and characterized.Compound 3 features a one-dimensional chain structure built by CztBu(PyriPr)2Fe units and bridged by end-to-end azido ligands. This chain material exhibits magnetic hysteresis at low temperatures and non-superimposable zero-field cooled and field cooled magnetization. These properties are consistent with single-chain magnet behavior, likely arising from superexchange coupling of Fe(II) centers via the azide bridges.

Double end-on azido derivative of a tridentate (NNO) Schiff base dimeric copper(II) complex: synthesis, X-ray structure, magnetic property and catalytic effectiveness

A dimeric copper(II) complex, bis{(2-[1-(aminoethylimino)ethyl]-phenoxo}-di-μ1,1-azido-dicopper(II), [Cu2(L)2(μ2-1,1-N3)2] (1) [L = 2-[1-(aminoethylimino)ethyl]-phenoxo ion], has been isolated using a self-assembly reaction using a 1:1:1 molar ratio of Cu(NO3)2·3H2O, HL and NaN3 in methanol at room temperature and characterized through X-ray diffraction analysis and spectroscopic studies. X-ray structural analysis reveals that 1 consists of two distinct dinuclear molecular units, where each copper(II) center in the individual dinuclear unit adopts a distorted square pyramidal geometry with a CuN4O chromophore ligated through a tridentate (NNO) Schiff base and two N atoms of two different bridging azides in µ1,1-mode. Two Cu(II) centers are linked through double µ2-1,1-N3 bridges to form the dinuclear unit [Cu2(L)2(μ2-1,1-N3)2]. In the crystalline state, the dinuclear units in 1 are associated through weak intermolecular N-H⋯O hydrogen bonds to afford a 2-D sheet structure viewed along the crystallographic a-axis. The small magnitude of the antiferromagnetic interaction (J = –0.45 cm−1) is a result of the long Cu···Cu separation (3.205(2) Å). The catalytic efficacy of 1 was studied in a series of solvents for the epoxidation of alkenes using tert-butyl-hydroperoxide (TBHP) as an efficient oxidant under mild conditions.

Iron(III), cobalt(II) and zinc(II) coordination compounds with a carboximidamide ligand: Synthesis, structures and properties

Coordination complexes of iron(III), cobalt(II) and zinc(II) with the ligand N′-{[1-(pyridin-2-yl)ethylidene]amino}pyridine-2-carboximidamide (pmhpa) have been synthesised and were structurally characterized by elemental analysis, mass spectrometry, X-ray diffraction and infrared spectroscopy. The mononuclear iron(III) complex, [Fe(pmhap)2][FeCl4], (1), adopts the orthorhombic non-centric space group P212121. The iron is present in an octahedral environment in the ion [Fe(pmhap)2]+. The crystallographically-determined formula of the cobalt(II) complex (2) is [Co2(pmhap)2Cl3]2[CoCl4].4MeOH. The compound crystallizes in the non-centric space group P4̄21c with a single cobalt ion in the asymmetric unit. The complex is dinuclear, with two cobalt ions bridged by chloride and the two nitrogen atoms of N=N of the pmhap ligand. The zinc(II) complex; [Zn2(pmhpa)3](NO3)4.2.75MeOH (3) crystallizes in the cubic space group Pa3̄ with disordered methanol molecules present. This is dinuclear with the two zinc atoms being bridged by three N=N links from the ligand to form a threefold symmetric rotor. Infrared spectroscopy confirms that coordination occurs through the azide bridge. Measurements of magnetic susceptibility for the iron(III) and cobalt(II) complexes show that they are paramagnetic between 5 and 300 K. Mössbauer spectroscopic data supports the structure of the iron(III) complex being composed of an octahedral and a tetrahedral iron atom.

1D Azido bridged Cu(II) coordination polymer with 1,3‐oxazolidine ligand as an effective catalyst for green click synthesis of 1,2,3‐triazoles

A new 1D azido bridged Cu(II) coordination polymer with 1,3‐oxazolidine based ligand, [Cu(H3L)(μ1,3‐N3)(N3)]n (1), was synthesized and characterized by elemental analysis and spectroscopic methods. The structure of 1 was also determined by single crystal X‐ray analysis which indicated the 1D polymeric chain is generated by end‐to‐end (EE) azide bridge. The obtained compound was employed as catalyst in green click synthesis of β‐hydroxy‐1,2,3‐triazoles from one‐pot three‐component cycloaddition reaction of epoxide‐azide‐alkyne. The catalytic reactions were carried out in water as a safe, cheap and green solvent. The catalytic studies indicated that the obtained 1D azido bridged Cu(II) coordination polymer is an active catalyst for preparing β‐hydroxy‐1,2,3‐triazoles. The effect of temperature on the selectivity of the catalytic system was studied and the results indicated this catalytic system has high selectivity at low temperatures. The structure the product obtained from the reaction of 2,3‐epoxypropylphenylether, azide and 1‐ethynyl‐1‐cyclohexanol (T4) was determined by single crystal X‐ray analysis. The results indicate Cu(II) coordination polymers can be a new class of catalytic systems for green click synthesis of 1,2,3‐triazoles.

Structure, DFT studies, magnetism and biological activity of bis[(µ-azido)-chloro-(1,10-phenanthroline)-copper(II)] complex

The dinuclear complex Bis[(µ-azido)-chloro-(1,10-phenanthroline)-copper(II)] (1) was synthesized, and characterized by X-ray. Complex (1) crystallizes in the monoclinic system, it consists of centrosymmetric [CuCl(phen)µ-N3]2 dimers bridged by azide groups. The phenanthroline ligand, chloride ion, and ƞ-N of equatorial bridging azide ligand are coplanar and the square pyramidal copper ion is displaced slightly out of this basal plane, toward the axial bridging azide. The presence of H-bonds, CH-π and π-π interactions form layers of type ABAB within the supramolecular structure of (1). The magnetic susceptibility of (1) versus temperature data showed a weak antiferromagnetic coupling between Cu(II) ions. The best fitting parameters were for g = 2.01 ± 0.01 and J = −0.55 ± 0.01 cm−1. Thermal analysis of (1) exhibited an exothermic peak due to decomposition of azide ligands. The calculated HOMO–LUMO gap from DFT is 0.03098 a.u. (0.08430 eV).Besides, complex (1) exhibited potent chemotherapeutic potential with strong activity after 48 h against MDA-MB-32 (breast adenocarcinoma), HT-29 (colon adenocarcinoma), A549 (lung adenocarcinoma), SF (astrocytoma) and B16F10 (melanoma) cell lines, with IC50 value 0.78 μg/ml (1.21 µM) which is several folds higher than cisplatin 4.88 μg/ml (16.3 µM). (1) also has a better therapeutic index and toxicological profile compared to cisplatin, as evidenced by the median lethal dose (LD50).

Effect of 3d heterometallic ions on the magnetic properties of azido-Cu(II) with isonicotinic acid coligands: A theoretical perspective

Based on density functional theory and the broken-symmetry approach, the magnetic properties of an azido-Cu(II) complex with isonicotinic acid coligands were studied at the B1LYP/def2-TZVP level. According to the molecular magnetic orbitals and Mulliken spin population analysis, there are strong orbital interactions between the paramagnetic CuII/NiII ions and the bridging azide ligands and isonicotinic ions. The supposedly empty 4s/4p/4d orbitals of the MII ions are found to play an important role in the mechanism of magnetic coupling and are probed using NBO analysis. As the number of unpaired electrons on the MII ions increases, the number of electrons that occupy the empty 4d orbitals with the highest energy and overlap integrals of the magnetic orbitals in the CuIIMII (M = Cu, Ni, Co, Fe, Mn) model complexes increases accordingly, and the magnetic coupling constant gradually decreases.

End-to-End Azido-Bridged Lanthanide Chain Complexes (Dy, Er, Gd, and Y) with a Pentadentate Schiff-Base [N3O2] Ligand: Synthesis, Structure, and Magnetism.

The syntheses, structure and magnetic properties are reported for five novel 1D polymeric azido-bridged lanthanide complexes with the general formula {[Ln(DAPMBH)(N3)C2H5OH]C2H5OH}n where H2DAPMBH = 2,6-diacetylpyridine bis(4-methoxybenzoylhydrazone)-a new pentadentate pyridine-base [N3O2] ligand and Ln = Dy (1), Y0.930Dy0.070 (2), Er (3), Y0.923Er0.077 (4), and Gd (5). X-ray diffraction analysis of 1-5 show that the central lanthanide atoms are eight-coordinated with the N5O3 donor set originating from the ligand DAPMBH, one coordinated ethanol molecule and two end-to-end type N3- bridges connecting the metal centers into infinite chain. The [LnN5O3] coordination polyhedron can be regarded as a distorted dodecahedron (D2d). AC magnetic measurements revealed that compounds 1-4 show field-induced single-molecule magnet behavior, with estimated energy barriers Ueff ≈ 47-17 K. The experimental study of magnetic properties was complemented by theoretical analysis based on crystal-field calculations. Direct current magnetic susceptibility studies revealed marginally weak intrachain exchange interaction between Ln3+ ions mediated by the end-to-end azide bridging groups (J ≈ -0.015 cm-1 for 5). Comparative analysis of static and dynamic magnetic properties of magnetically concentrated (1, 3) and diluted (2, 4) Dy and Er compounds showed that, despite fascinating 1D azido-bridged chain structure, compounds 1 and 3 are not single-chain magnets; their magnetic behavior is largely due to single-ion magnetic anisotropy of individual Ln3+ ions.

Crystal structure and photoluminescence properties of catena-poly[[bis-(1-benzyl-1H-imidazole-κN 3)cadmium(II)]-di-μ-azido-κ4 N 1:N 3

The new title one-dimensional CdII coordination polymer, [Cd(C10H10N2)2(μ1,3-N3)2] n , has been synthesized and structurally characterized by single-crystal X-ray diffraction. The asymmetric unit consists of a CdII ion, one azide and one 1-benzyl-imidazole (bzi) ligand. The CdII ion is located on an inversion centre and is surrounded in a distorted octa-hedral coordination sphere by six N atoms from four symmetry-related azide ligands and two symmetry-related bzi ligands. The CdII ions are linked by double azide bridging ligands within a μ1,3-N3 end-to-end (EE) coordination mode, leading to a one-dimensional linear structure extending parallel to [100]. The supra-molecular framework is stabilized by the presence of weak C-H⋯N inter-actions, π-π stacking [centroid-to-centroid distance of 3.832 (2) Å] and C-H⋯π inter-actions between neighbouring chains.

Electrocatalytic properties of a dinuclear cobalt(III) coordination compound in molecular oxygen reduction reaction

A new dinuclear cobalt(III) coordination compound, [Co2L(μ‐N3)(N3)2]·CH3OH (1), was synthesized and characterized by elemental analysis, spectroscopic methods, and single‐crystal X‐ray analysis in which H3L is a heptadentate ligand obtained by the condensation of triethylenetetramine with 5‐bromo‐2‐hydroxybenzaldehyde. X‐ray analysis revealed that two cobalt(III) ions have distorted octahedral geometry and are connected together by a phenoxy and an azide bridging ligand. The catalytic activity of compound 1 for oxygen (O2) reduction reaction was investigated. Compound 1 can efficiently catalyze the reduction of O2 by a weak electron donor, ferrocene (Fc), at the polarized water–1,2‐dichloroethane interface. It was found that compound 1 can catalyze O2 reduction to H2O2, whereas in the presence of Fc, it can catalyze the reduction of O2 to water.

Synthesis, structure and bioactivity of Ni2+ and Cu2+ acylhydrazone complexes.

Two acylhydrazone complexes, bis{6-methyl-N'-[1-(pyrazin-2-yl-κN1)ethylidene]nicotinohydrazidato-κ2N',O}nickel(II), [Ni(C13H12N5O)2], (I), and di-μ-azido-κ4N1:N1-bis({6-methyl-N'-[1-(pyrazin-2-yl-κN1)ethylidene]nicotinohydrazidato-κ2N',O}nickel(II)), [Cu2(C13H12N5O)2(N3)2], (II), derived from 6-methyl-N'-[1-(pyrazin-2-yl)ethylidene]nicotinohydrazide (HL) and azide salts, have been synthesized. HL acts as an N,N',O-tridentate ligand in both complexes. Complex (I) crystallizes in the orthorhombic space group Pbcn and has a mononuclear structure, the azide co-ligand is not involved in crystallization and the Ni2+ centre lies in a distorted {N4O2} octahedral coordination environment. Complex (II) crystallizes in the triclinic space group P-1 and is a centrosymmetric binuclear complex with a crystallographically independent Cu2+ centre coordinating to three donor atoms from the deprotonated L- ligand and to two N atoms belonging to two bridging azide anions. The two- and one-dimensional supramolecular structures are constructed by hydrogen-bonding interactions in (I) and (II), respectively. The in vitro urease inhibitory evaluation revealed that complex (II) showed a better inhibitory activity, with the IC50 value being 1.32±0.4 µM. Both complexes can effectively bind to bovine serum albumin (BSA) by 1:1 binding, which was assessed via tryptophan emission-quenching measurements. The bioactivities of the two complexes towards jack bean urease were also studied by molecular docking. The effects of the metal ions and the coordination environments in the two complexes on in vitro urease inhibitory activity are preliminarily discussed.

Synthesis, structure and magnetic properties of copper(ii) azide.

A novel azide-bridged copper compound without an auxiliary ligand has been synthesized and characterized by single-crystal diffraction analysis. The compound consists of 1D double chains with end-on (EO) azide bridges. Furthermore, the neighboring chains are connected by weak coordination bonds, which leads to the formation of a 3D architecture. Low-temperature magnetic measurements reveal that antiferromagnetic interactions are dominant, with concomitant spin-canted antiferromagnetism.

Syntheses, crystal structures and photo physical aspects of azido-bridged tetranuclear cadmium (II) complexes: DFT/TD-DFT, thermal, antibacterial and anti-biofilm properties

In this work we have reported two novel tetranuclear Cd(II) complexes viz. [Cd4 (LOMe)2 (μ1,1-N3)3 (μ1,3-N3)]n (1) and [Cd4 (LOEt)2 (μ1,1-N3)3(OAc)]2 (2) where (H2LOMe) and (H2LOEt) are two important less explored salen-type Schiff base ligands. Both of the complexes have been characterized by using routine spectroscopic techniques, elemental analyses (C, H and N), X-ray powder diffraction pattern (PXRD) and thermal analysis by TGA along with single x-ray crystallography. The complete structural study discloses that in both cases the fully deprotonated ligand [LOMe]2- or [LOEt]2- utilized all potential coordination sites to accommodate four Cd(II) ions. Complex 1 is a one-dimensional polymer with azide (N3) linkage having both (μ1,1 end on) and (μ1,3 end-to-end) azido bridging but complex 2 is a discrete octanuclear ensamble where two [Cd4(O)4(N)2]2+ units bridged to each other showing μ1,1 end on end on azide bridging. Exploration of photo physical properties in DMSO solvent reveals that Cd(II) complexes enhance appreciably the fluorescence behavior over free Schiff base ligands (H2LOMe) and (H2LOEt). DFT calculations performed at B3LYP/def2-TZVP level of theory reveal both the energetics and composition of FMOs in these complexes and also show electrophilic and nucleophilic areas via molecular electrostatic maps [ESP] concept. The antibacterial, membrane damage assay and anti-biofilm properties of complexes 1 and 2 were investigated very carefully against some important Gram-positive and Gram-negative bacterial strains.

Synthesis and characterization of pseudohalide-metal(II) complexes with 4-methoxypyridine as co-ligand

Four metal(II) pseudohalide complexes with 4-methoxypyridine (4-MOP) as co-ligand have been synthesized, [Cu(4-MOP)2(N3)2]n (1), [Zn(4-MOP)2(N3)2]n (2), [Co(4-MOP)4(N3)2] (3), and [Co(4-MOP)4(NCO)2] (4) and characterized by IR, UV–Vis spectroscopy and single crystal X-ray diffraction. The polymeric 1-D complex of 1 features double end-on bridging azide groups and terminal 4-MOP ligands in trans-conformation around the distorted Cu(II) octahedra, whereas compounds 2–4 form monomeric complexes with tetrahedral Zn(II) and octahedral Co(II) centers. The magnetic properties of 1 and the thermoanalytical behaviour of 4 are reported.

Mixed metal CoII 1-x ZnII x -organic frameworks based on chains with mixed carboxylate and azide bridges: magnetic coupling and slow relaxation.

A series of isomorphous three-dimensional metal–organic frameworks [CoII1−xZnIIx(L)(N3)]·H2O (x = 0.26, 0.56 and 0.85) based on bimetallic CoII1−xZnIIx (x = 0.26, 0.56 and 0.85) chains with random metal sites have been synthesized and magnetically characterized. The CoII1−xZnIIx series, which intrinsically feature random anisotropic/diamagnetic sites, shows complex magnetic interactions. By gradually introducing the diamagnetic ZnII ions into the pure anisotropic CoII single-chain magnets system, the ferromagnetic interactions between CoII ions are gradually diluted. Moreover, the slow magnetic relaxation behaviour of the mixed metal CoII1−xZnIIx systems also changes. In this bimetallic series CoII1−xZnIIx, the Co-rich materials exhibit slow relaxation processes that may arise from SCM mechanism, while the ZnII-rich materials show significantly low slow magnetic relaxation. A general trend is that the activation energy and the blocking temperature decrease with the increase in diamagnetic ZnII content, emphasizing the importance of anisotropy for slow relaxation of magnetization.