Nitrile Nitrogen Atoms Research Articles

Comparison of In Vitro and In Vivo Biological Screening of Nano‐Palladium (II) and Platinum (II)‐Based Compounds With DFT and Molecular Docking Study

ABSTRACTWithin the current challenges in medicinal chemistry, the creation of novel and improved therapeutic agents stands out. 2‐Cyano‐3‐(thiophen‐2‐yl)prop‐2‐enethioamide (CTPTA) ligand was complexed with palladium (II) and platinum (II) ions within the nanoscale with the molecular formula [M (CTPTA)Cl2]. H2O. The CTPTA ligand and its complexes were characterized by elemental analysis, UV–Vis spectra, FTIR, mass spectra, TGA, magnetic measurement, and the molar conductance technique. Analysis with a scanning electron microscope (SEM) revealed that the nanostructure dimension of both complexes is predominantly between 10 and 30 nm. The CTPTA ligand functions as a bidentate ligand, utilizing thione sulfur, and cyanide nitrogen atoms. Density functional theory was employed to analyze the geometric structure properties of the CTPTA ligand and its complexes. Natural population (NPA) and Mulliken population (MPA) methods were used to calculate the charge distribution. The cytotoxic impact results of all compounds on human liver cancer (HepG2) cell line were satisfactory. The ligand and its complexes were also tested against gram‐negative and gram‐positive bacteria in vitro. The findings of the molecular docking study supported the cytotoxicity and antibacterial effects. The antioxidant and anti‐inflammation activities of synthesized palladium (II) and platinum (II) complexes had a great spectrum of activity. The preclinical pharmacokinetic studies on albino rats revealed that the newly studied complexes achieved excellent antitumor results. This was clear in the investigated parameters, especially the amelioration of AFP levels, liver weight, oxidative stress, and lobular hepatic architecture injury.

Synthesis of an alternating copolymer of the dense 1,2,3‐triazole backbone carrying t‐butyl ester and nitrile side chains

AbstractIn these decades, synthesis of polymers with controlled monomer sequences has been of increasing importance in polymer chemistry. When we tested synthesis of a heterodimer of 4‐azido‐5‐hexynoic acid derivatives carrying t‐butyl (tBu) ester and tBu amide side chains for preparation of an alternating copolymer, we unexpectedly obtained a heterodimer precursor carrying tBu ester and nitrile side chains, in a high yield. Since dense 1,2,3‐triazole polymers carrying nitrile side chains are expected as a new functional polymer, the heterodimer is polymerized by copper(I)‐catalyzed azide–alkyne cycloaddition polymerization to obtain an alternating copolymer carrying tBu ester and nitrile side chains in this study. Since 1,2,3‐triazole and nitrile moieties are known to be ligands for metal ions, the complex formation of the alternating copolymer with PdCl2 is also investigated by NMR. In the presence of PdCl2, 1H NMR spectra show broad and separated signals due to the free and complexed copolymers, indicative of slow exchange. Pulse‐field‐gradient spin‐echo NMR data indicated that the coordination of alternating copolymer to PdCl2 made the copolymer chains take a more compact conformation under dilute conditions. The density functional theory calculations indicated that the alternating copolymer coordinated to PdCl2 preferentially through the 1,2,3‐triazole nitrogen and nitrile nitrogen atoms.

Ferromagnetically coupled single-chain magnets exhibiting a magnetic hysteresis of 0.42 Tesla in cyano-bridged FeIII2MII (M = Ni, Fe) coordination polymers.

The synthesis, single-crystal structures and magnetic properties of two new double-zigzag-chain cyano-bridged heterobimetallic {[MII(Py-NOH)2][FeIII(Tp*)(CN)3]2}·H2O ([FeIII2MII]) (Py-NOH = 4-pyridinealdoxime, Tp* = tris(3,5-dimethylpyrazol-1-yl)borohydride, M = Ni (1), Fe (2)) compounds are reported. The crystal structures of both compounds were determined by single-crystal X-ray diffraction. Complexes 1 and 2 are isostructural, with the crystal structure comprising neutral double-zigzag (4,2-ribbon-like) bimetallic chains. The FeIII ion is coordinated by three cyanide carbon atoms and three nitrogen atoms of Tp* anions. However, the MII ion is surrounded by four cyanide nitrogen atoms and two nitrogen atoms from two Py-NOH ligands. The crystal structures and magnetic studies demonstrate that both complexes behave as single-chain magnetics (SCMs) with intrachain ferromagnetic coupling. Furthermore, [FeIII2NiII] exhibits an excellent coercive field of 0.42 T at 1.8 K, among cyano-bridged 3d transition-metal-based SCMs reported thus far. Preliminary theoretical calculations provide a deep understanding of the magnetic properties of [FeIII2NiII].

Manipulating fluorescence by photo-switched spin-state conversions in an iron(ii)-based SCO-MOF.

Manipulating fluorescence by photo-switched spin-state conversions is an attractive prospect for applications in smart magneto-optical materials and devices. The challenge is how to modulate the energy transfer paths of the singlet excited state by light-induced spin-state conversions. In this work, a spin crossover (SCO) FeII-based fluorophore was embedded into a metal-organic framework (MOF) to tune the energy transfer paths. Compound 1 {Fe(TPA-diPy)[Ag(CN)2]2}·2EtOH (1) has an interpenetrated Hofmann-type structure, wherein the FeII ion is coordinated by a bidentate fluorophore ligand (TPA-diPy) and four cyanide nitrogen atoms and acts as the fluorescent-SCO unit. Magnetic susceptibility measurements revealed that 1 underwent an incomplete and gradual spin crossover with T1/2 = 161 K. Photomagnetic studies confirmed photo-induced spin state conversions between the low-spin (LS) and high-spin (HS) states, where the irradiation of 532 and 808 nm laser lights converted the LS and HS states to the HS and LS states, respectively. Variable-temperature fluorescence spectra study revealed an anomalous decrease in emission intensity upon the HS → LS transition, confirming the synergetic coupling between the fluorophore and SCO units. Alternating irradiation of 532 and 808 nm laser lights resulted in reversible fluorescence intensity changes, confirming spin state-controlled fluorescence in the SCO-MOF. Photo-monitored structural analyses and UV-vis spectroscopic studies demonstrated that the photo-induced spin state conversions changed energy transfer paths from the TPA fluorophore to the metal-centered charge transfer bands, ultimately leading to the switching of fluorescence intensities. This work represents a new prototype compound showing bidirectional photo-switched fluorescence by manipulating the spin states of iron(ii).

Ligand Modified and Light Switched On/Off Single-Chain Magnets of {Fe 2 Co} Coordination Polymers via Metal-to-Metal Charge Transfer

Ligand Modified and Light Switched On/Off Single-Chain Magnets of {Fe ₂ Co} Coordination Polymers via Metal-to-Metal Charge Transfer

Heterometallic supramolecular architectures constructed from cyanido-based [CoIII(AA)(CN)4]- building-blocks (AA = 1,10-phenantroline and 2,2’-bipyridine)

A neutral, mixed-valence cyanido-bridged {Co2IICo2III} complex, with formula {[CoII2(L)(MeOH)2][CoIII(phen)(CN)4]2}·2H2O·0.5MeOH (1), and a cyanido-based ionic compound, with formula [MnII(MAC)(H2O)2][CoIII(bipy)(CN)4]2·3H2O (2) were obtained by reacting the heteroleptic Ph4P[CoIII(AA)(CN)4] building-block [AA = 1,10-phenanthroline, phen, (1) and 2,2’-bipyridine, bipy, (2)] with the dinuclear {Co2IIL}2+ (1) and mononuclear {MnII(MAC)}2+ (2) precursors, respectively [H2L = macrocyclic Schiff-base obtained by condensation of 2,6-diformyl-p-cresol with 1,3-diaminopropane and MAC = 2,13-dimethyl-3,6,9,12,18-pentaazabicyclo-[12.3.1]octadeca-(18),2,12,14,16-pentaene]. The structures of 1 and 2 were determined by X-ray diffraction on single crystals. 1 is a neutral tetranuclear homometallic compound where two peripheral [CoIII(phen)(CN)4]- entities which act as end-cap ligands through one of its four cyanide groups towards the inner double phenoxido-bridged [Co2II(L)(MeOH)2]2+ dinuclear unit. Both cobalt(III) and cobalt(II) ions are six-coordinate with two phenanthroline-nitrogen and four cyanide-carbon atoms (at CoIII) and two phenoxido-oxygens and two imino-nitrogen atoms from the Schiff-base ligand plus a methanol molecule and a cyanide-nitrogen atom (at CoII) building somewhat distorted octahedral surroundings. The value of the cobalt(II)×××cobalt(II) separation is 3.11 Å and that of the angle at the phenoxo bridge is 99.4°. Compound 2 is a heterobimetallic ionic salt which is made up of [CoIII(bipy)(CN)4]- anions and [Mn(MAC)(H2O)2]2+ cations. Each cobalt(II) in 1 is six-coordinated, in a distorted octahedral environment built by a bidentate bipy ligand and four monodentate cyanide groups whereas the manganese(II) ion is seven-coordinated with five nitrogen atoms of the MAC ligand and two water molecules describing a distorted pentagonal bipyramid surrounding. The cryomagnetic investigation of 1 in the temperature range 1.9-300 K reveals the occurrence of strong spin-orbit coupling effects and a relatively weak antiferromagnetic interaction between the high-spin cobalt(II) ions linked by the double phenoxido bridge . The nature and magnitude of the magnetic coupling in 1 compares well with those from previous magneto-structural studies on the CoII2O2 motifs where antiferromagnetic interactions result in the examples having values at the phenoxido angle larger than 99.7º with dihedral angles smaller than 35.3°.

Trans-Diamminebis(1,2-di-cyano-ethene-1,2-di-thiol-ato)platinum(IV).

The title compound, [Pt(C4N2S2)2(NH3)2], represents an octa-hedral platinum(IV) complex with two trans-ammine and two mnt (mnt = 1,2-di-cyano-ethene-1,2-di-thiol-ato) ligands. The Pt-N and Pt-S distances are consistent with those in other platinum(IV) complexes. As a result of a slight canting of the coordination of the mnt ligand to the platinum(IV) atom, the nitrile nitro-gen atoms are positioned suitably to hydrogen-bond with adjacent ammines.

The Influence of d‐f Coupling on Slow Magnetic Relaxation in NiIILnIIIMIII (Ln = Gd, Tb, Dy; M = Cr, Fe, Co) Clusters

Five heterotrimetallic 3d‐3d′‐4f complexes, [Ni(L)Dy(H2O)4][Cr(CN)6]·3H2O (1), [Ni(L)Dy(H2O)4][Fe(CN)6]·3H2O (2), [Ni(L)Dy(H2O)4][Co(CN)6]·3H2O (3), [Ni(L)Tb(H2O)4][Co(CN)6]·3H2O (4), and [Ni(L)Gd(H2O)4][Co(CN)6]·3H2O (5) (H2L = N,N‐ethylenebis(3‐methoxysalicylaldiimine)), were prepared and characterized to study the influence of d‐f coupling on the magnetic behavior of such NiIILnIIIMIII (Ln = Gd, Tb, Dy; M = Cr, Fe, Co) clusters. The X‐ray analysis revealed clearly their heterotrimetallic trinuclear structures, in which the [Ni(L)Ln(H2O)4]3+ moiety is further coordinated by one cyanide nitrogen atom from [M(CN)6]3–, forming the peculiar trinuclear NiIITbIIIMIII entity. The magnetic measurements revealed the typical slow magnetic relaxation expected for these 3d–3d′–4f systems. Interestingly, the slow magnetic relaxation is highly affected by the d‐f magnetic coupling, which indeed highlights the importance of tuning the d‐f magnetic coupling to obtain improved magnetic properties.

Low-dimensional compounds containing cyanido groups. Part XXXIV. Structure, spectral and magnetic properties of the first complex with pyridylbenzimidazole and nonlinear pseudohalide anion

Abstract From the system CuCl2 – pbi – NaN(CN)2 −, polymeric [CuCl(μ1,5-dca)(pbi)]n·nH2O (1) complex (dca=dicyanamide, pbi=2-(2-pyridyl)benzimidazole) was isolated and characterized by structure analysis, spectral and magnetic measurements. Infrared spectroscopy confirmed the presence of pbi, dca and water molecules in 1. Its solid-state structure is formed by infinite chains running along the b axis. In the chain, the Cu(II) atom is penta-coordinated by two nitrogen atoms of chelate pbi ligand, by two nitrile nitrogen atoms of bridging μ1,5-dca and by chloride ligand which occupies the apical position of tetragonal pyramid around the Cu(II) atom. Asymmetric unit is supplemented by one molecule of solvated water, which along with chlorine atom serves as acceptors in intermolecular hydrogen bonds and along with π–π interactions create a 3D supramolecular structure. Magnetic measurements revealed the presence of a weak ferromagnetic exchange interaction J/kB =0.11 K.

Systematic evaluation and refinement of existing all-atom force fields for the simulation of liquid acetonitrile.

The reliability of a molecular dynamics (MD) simulation study mainly depends on the accuracy of the applied force field. Unlike the ability of some potential models for reasonably predicting the thermodynamic properties of acetonitrile (ACN), simulated dynamical properties such as self-diffusion are generally underestimated compared to experimental values. The present work focuses on the evaluation and refinement of several available all-atom force fields for ACN and proposes a refined flexible six-site potential model. The main modification is related to the reduction of intermolecular LJ parameters (σ and ɛ) for hydrogen atoms, especially ɛ, significantly affecting the dynamical behavior. Besides, the adjustment of σ and ɛ for nitrile carbon and nitrogen atoms helps reach optimum results. Our refined model shows an excellent agreement with the experiment for self-diffusion coefficient and thermodynamic quantities as well as providing a qualitative description of the microscopic structure of liquid ACN. © 2018 Wiley Periodicals, Inc.

Synthesis, crystal structures and magnetic properties of cyanide-bridged heterobimetallic trinuclear Cr 2 III MnII complexes based on the cis-dicyanidemetalate [Cr(2,2′-bipy)2(CN)2]ClO4 building block

A structurally characterized cis-dicyanidemetalate [Cr(2,2′-bipy)2(CN)2]ClO4 (1) building block and two mononuclear seven-coordinate macrocyclic manganese(II) complexes have been employed to assemble two cyanide-bridged heterometallic CrIII–MnIII complexes: {[Mn(L1)][Cr(2,2′-bipy)2(CN)2]2}{ClO4}4·H2O (2) and {[Mn(L2)][Cr(2,2′-bipy)2(CN)2]2}{ClO4}4·2H2O (3) (L1 = 2,13-dimethyl-3,6,9,12,18-pentaazabicyclo[12.3.1]octadeca-1(18),2,12,14,16-pentaene, L2 = 2,13-dimethyl-6,9-dioxa-3,12,18-triazabicyclo[12.3.1]octadeca-1(18),2,12,14,16-pentaene). Single-crystal X-ray diffraction analysis shows that 2 and 3 have similar cyanide-bridged cationic trinuclear Cr2Mn structures with free ClO4 − as balancing anions, in which the cyanide precursor acts as a monodentate ligand to connect the macrocyclic manganese(II) units. The coordination geometry of the manganese(II) centers in the two complexes is slightly distorted pentagonal-bipyramidal, with two cyanide nitrogen atoms at the trans-positions and N5 or N3O2 donor sets in the equatorial plane provided by the macrocyclic ligand. Investigation of the magnetic properties reveals antiferromagnetic magnetic coupling between the cyanide-bridged Cr(III) and Mn(II) centers. A best-fit analysis of the magnetic susceptibility leads to the magnetic coupling constants J = −1.15 and −1.08 cm−1 for complexes 2 and 3, respectively.

Three 1D cyanide-bridged M(Ni, Pd, Pt)-Mn(II) coordination polymer: synthesis, crystal structure and magnetic properties

Three tetracyanide-containing building blocks K2[M(CN)4] (M = Ni, Pd, Pt) and one semi-closed macrocycle seven-coordinated manganese(II) compound have been employed to assemble cyanide-bridged heterometallic complexes, resulting in three cyanide-bridged MII-MnII complexes: [Mn(L)][Ni(CN)4] · 2H2O (1) [Mn(L)][Pd(CN)4] (2) and [Mn(L)][Pt(CN)4] (3) (L = 2,6-bis[1-(2-(N-methylamino)ethylimino)ethyl]pyridine). Single-crystal X-ray diffraction analysis shows their similar one-dimensional structure consisting of the alternating [Mn(L)]2+ species and [M(CN)4]2- building blocks, generating a cyanide-bridged neutral polymeric chain. In all three isostructural complexes the coordination geometry of manganese ion is a slightly distorted pentagonal-bipyramidal with the two cyanide nitrogen atoms at the trans positions and N5 coordinating mode at the equatorial plane from ligand L. Investigation over magnetic properties of these complexes reveals very weak antiferromagnetic interaction between neighboring Mn(II) ions bridged by the long NC-M-CN unit. A best-fit to the magnetic susceptibility of complexes 1-3 leads to the magnetic coupling constant of J = -0.081, -0.103 and -0.14 cm-1, respectively.

Molecular structures of (5656)macrotetracyclic chelates in M(II) ion–ethanedithioamide–methanimine–hydrogen cyanide quaternary systems by DFT calculations

The geometric parameters of Mn(II), Fe(II), Co(II), Ni(II), Cu(II), and Zn(II) (5656)macrotetracyclic complexes with the NNNN-coordination of the donor cites of the chelant, which can be formed upon template processes in M(II)–ethanedithioamide–methanimine–hydrogen cyanide quaternary systems, have been calculated using the density functional (DFT) hybrid method in the OPBE/TZVP approximation with the use of the Gaussian09 program package. It is shown that no one of the 5-membered chelate rings is planar, and these rings are not identical in the complexes studied. The 6-membered chelate rings are likewise not identical: one has a prominent noncoplanarity, and the other is almost planar. In all metal complexes, the nitrile nitrogen atom in one 6-membered ring noticeably departs from the plane of the ring, and in the other 6-membered ring, the respective nitrogen atom lies virtually in the plane of the ring.

Synthesis, crystal structure and magnetic property of one-dimensional heterometallic cyanide-bridged complex: {[Cu(hmpH)2Cu(hmp)(hmpH)Co(μ-CN)4(CN)2]·2H2O}n

A novel one-dimensional (1D) coordination polymer, {[Cu(hmpH)2Cu(hmp)(hmpH)Co(μ-CN)4(CN)2]·2H2O}n (1) (hmpH=2-pyridinemethanol), was synthesized and characterized by elemental analysis, spectral (FT-IR, Raman and EPR) methods, thermal analysis, single crystal X-ray diffraction and magnetic measurement techniques. In 1, the Co(III) ions are six coordinated with six cyanide-carbon atoms in a octahedral arrangement. The Cu1 and Cu2 ions are coordinated with two cyanide-nitrogen atom, two nitrogen and two oxygen atoms from chelating two hmpH and hmpH/hmp ligands, respectively. The hmpH ligand in the complex has behaved as both anionic ligand (with its hydroxyl group being deprotonated) and as neutral form with the preserved OH group. The hydrogen bonding interactions between the crystal water molecules and hydroxyl group of hmpH ligands extends structure to the two dimensional (2D) supramolecular structure. The 2D layers were extended into 3D supramolecular networks by π⋯π and C–H⋯π interactions between pyridine rings of hmpH ligands. Variable temperature magnetic susceptibility measurement recorded in the 10–300K range showed the presence of a very small antiferromagnetic within chains through CN bridges. Thermal stability and decomposition reactions of the complex take place in the temperature range 30–950°C in a dry air atmosphere.

5-(2-Hydroxybenzoyl)-2-(1H-indol-3-yl)pyridine-3-carbonitrile

In the title compound, C21H13N3O2, the indole and pyridine rings are planar. The pyridine ring is in an antiperiplanar (−ap) orientation with the indole ring system and an antiperiplanar (+ap) orientation with the hydroxyphenyl ring. An intramolecular O—H...O hydrogen bond stabilizes the molecular structure. In the crystal, N—H...N hydrogen bonds involving the indole NH group and the cyanide nitrogen atom lead to the formation of a two-dimensional supramolecular network lying parallel to (011).

One-dimensional cyanide- and fumarate-bridged heteronuclear complex, poly[μ-fumaratotetraaminedizinc(II)di-μ-cyanodicyanonickel(II) dihydrate

Abstract Cyanide- and fumarate-bridged bimetallic complex, poly[μ-fumaratotetraaminedizinc(II)di-μ-cyanodicyanonickel(II) dihydrate], {[Zn2(μ-fum)(NH3)4Ni(μ-CN)2(CN)2]·2H2O}n (1) (H2fum = Fumaric acid) was synthesized and structurally characterized by vibrational (FT-IR and Raman) spectroscopy, single crystal X-ray diffraction and elemental and thermal analyses techniques. The structure of the complex consists of a one-dimensional polymeric chain, in which the Zn(II) and Ni(II) ions are linked by CN groups. The Ni(II) ion is four coordinated with four cyanide-carbon atoms in a square planar arrangement and the Zn(II) ions are four coordinated with one cyanide nitrogen atom, two amine nitrogen atoms and one fumarate oxygen atom, in a distorted tetrahedral arrangement. In the complex, the adjacent chains are connected by strong O–H···O, O–H···N, N–H···O and N–H···N hydrogen bonding interactions to form a three dimensional network.

Coordination Chemistry of Cyclic Disilylated Germylenes and Stannylenes with Group 11 Metals.

Reactions of Et3P adducts of bissilylated germylenes and stannylenes with gold, silver, and copper cyanides led to cyanogermyl or -stannyl complexes of the respective metals. In the course of the reaction the phosphine moved to the metal, while the cyanide migrated to the low-coordinate group 14 element. The respective gold complexes were found to be monomeric, whereas the silver and copper complexes exhibited a tendency to dimerize in the solid state. Attempts to abstract the phosphine ligand with B(C6F5)3 led only to the formation of adducts with the borane coordinating to the cyanide nitrogen atom.

Synthesis, structures, and magnetic properties of a cyano-bridged Fe(III)2Fe(II) chain with long-range antiferromagnetic ordering

A novel cyano-bridged mixed-valence Fe(III)2Fe(II) chain with long-range antiferromagnetic ordering [Fe(III)(Tp)(CN)3]2Fe(II)(CH3OH)2⋅2CH3OH (1) (Tp=Tris(pyrazolyl)hydroborate) has been synthesized. The molecular structure has been determined by single-crystal X-ray diffraction. In compound 1, the FeIII ion was coordinated by three cyanide carbon atoms and three nitrogen atoms of Tp anions. Whereas, the FeII ion was surrounded by four cyanide nitrogen atoms and two oxygen atoms from two methanol molecules. The long-range antiferromagnetic ordering observed in complex 1 was presumably due to interchain magnetic dipolar interactions.

Binuclear complex [Cu(bappz)(μ-NC)Ni(CN)3]·H2O (bappz = 1,4-bis(3-aminopropyl)piperazine)

The novel bimetallic compound [Cu(bappz)(μ-NC)Ni(CN)3]·H2O (bappz = 1,4-bis(3-aminopropyl) piperazine) is prepared by the reaction of Cu(NO3)·3H2O, bappz, and K2[Ni(CN)4] in water. The complex is characterized by IR spectroscopy and single crystal X-ray diffraction. The neutral [Cu(bappz)(μ-NC)Ni(CN)3] complex assumes a cyanide-bridged binuclear structure in which the nickel(II) ion is four-coordinated by carbon atoms from four cyano groups (one of them forms a bridge) in a square planar arrangement, whereas the copper(II) ion is five-coordinated by four bappz nitrogen and one cyanide nitrogen atoms in a distorted square-pyramidal geometry.

Synthesis, structure, and magnetic properties of heterotrimetallic tetranuclear complexes

Two novel heterotrimetallic tetranuclear complexes [Cu(H2L)(CH3OH)]2Gd(DMF)Fe(CN)6·2H2O·DMF (1) and [Cu(H2L)(CH3OH)]2Tb(H2O)0.57(DMF)0.43Fe(CN)6·5.5H2O (2) are reported (H4L = N,N′-ethylenebis(3-hydroxysalicylidene)). The central Ln(III) ion is surrounded by two neutral [Cu(H2L)(CH3OH)] moieties, forming a Cu2Ln trinuclear unit. The [Fe(CN)6]3− anion is weakly coordinated to one Cu(II) ion of [Cu(H2L)(CH3OH)] through a cyanide nitrogen atom with the N–Cu distance of ca. 3.2 A. Magnetic susceptibility measurements indicate the presence of overall ferromagnetic interactions in complexes 1 and 2. The magnetic coupling constant in complex 1 is J Cu1Gd1 = 4.54 cm−1 and J Cu2Gd1 = 7.97 cm−1 based on \( \hat{H} = - 2J_{\text{Cu1Gd1}} \hat{S}_{\text{Cu1Gd1}} - 2J_{\text{Cu2Gd1}} \hat{S}_{\text{Cu2Gd1}} \). Dynamic AC magnetic susceptibility studies reveal that complex 2 shows frequency-dependent out-of-phase signals, typical of single molecule magnet behavior. The energy barrier for complex 2 under a 2 kOe applied DC magnetic field is 13 K.