Space Group P2 Research Articles

Enantiomorphic single component conducting nickel(II) and platinum(II) bis(diethyl-dddt) crystalline complexes.

Monoanionic and neutral nickel(II) and platinum(II) bis(dithiolene) complexes based on the 5,6-diethyl-5,6-dihydro-1,4-dithiin-2,3-dithiolate (de-dddt) chiral ligand have been prepared in racemic and enantiopure forms. Neutral closed-shell species have been generated from monoanionic precursors upon electrocrystallization. The racemic anionic (TBA)[Ni(S,S-de-dddt)(R,R-de-dddt)] complex crystallized in the centrosymmetric space group P21/c, while the neutral complexes crystallized in the enantiomorphic tetragonal space group P41212 or P43212. Very subtle conformational differences concerning the orientation of the ethyl substituents are observed between the racemic and the enantiopure compounds, thus impacting the intermolecular interactions at the nanoscale level. Indeed, in the former, the ethyl substituents are all-axial in both independent complexes, while in the latter, one of the independent complexes shows a mixed (eq, eq, ax, ax) conformation and the other independent complex of the asymmetric unit shows the all-axial conformation. Such a tenuous difference at the molecular/nanoscale level strongly impacts the conductivity of the materials. Temperature dependent high pressure single crystal conductivity measurements show activated conductivity for all the materials, with room temperature conductivity values of up to 1.3 × 10-3 S cm-1 for [Ni(S,S-de-dddt)2] at 12.3 GPa and 3.0 × 10-4 S cm-1 for [Pt(R,R-de-dddt)2] at 12.9 GPa. Nevertheless, the racemic compounds are more conductive, i.e. 3.8 × 10-2 S cm-1 for [Ni(rac-de-dddt)2] at 10.0 GPa and 1.5 × 10-3 S cm-1 for [Pt(rac-de-dddt)2] at 10.5 GPa, in agreement with the shorter and more numerous S⋯S intermolecular contacts observed in the crystal structures of the racemic complexes. Moreover, a detailed analysis of DFT calculations suggests that smaller band gaps and higher conductivities should occur for the racemic solids and for the Pt versus Ni complexes.

Strontioborite: revalidation as a mineral species and new data

Abstract Strontioborite, which was first described in 1960 and later discredited by the then named Commission on New Minerals and Mineral Names of the International Mineralogical Association (IMA CNMMN), has been re-investigated (electron microprobe, single-crystal and powder X-ray diffraction, crystal structure determination and IR spectroscopy) on two specimens, including the holotype, and revalidated by the IMA Commission on New Minerals, Nomenclature and Classification (CNMNC). Strontioborite is known only at the Chelkar salt dome (North Caspian Region, Western Kazakhstan), in halite rocks with bischofite, magnesite, anhydrite, halurgite, boracite, ginorite and celestine. It forms colourless lamellar, scaly or tabular crystals up to 2 mm across. The chemical composition (wt.%, H2O is calculated for (OH)4 = 4 H apfu, according to structural data; holotype/neotype) is: CaO 1.42/0.27, SrO 23.10/23.79, B2O3 67.37/67.57, H2O 8.73/8.72, total 100.62/100.37. The empirical formulae [calculated based on 15 O apfu = O11(OH)4 pfu] of the holotype and neotype specimens are Sr0.92Ca0.10B7.98O11(OH)4 and Sr0.95Ca0.02B8.02O11(OH)4, respectively. The idealised formula is Sr[B8O11(OH)4]. Strontioborite is monoclinic, space group P21, a = 7.6192(3), b = 8.1867(2), c = 9.9164(3) Å, β = 108.357(4)°, V = 587.07(3) Å3 and Z = 2. The strongest reflections of the powder X-ray diffraction pattern [d,Å(I)(hkl)] are: 7.22(100)(100), 5.409(61)(110), 4.090(64)(020), 3.300(48)(210), 2.121(30)( $\bar{1}$ 24) and 2.043(37)(040, 024, $\bar{2}$ 24). The crystal structure, solved from single-crystal X-ray diffraction data (R = 0.0372), is based upon the (100) layers of polymerised B–O–OH polyanions [B8O11(OH)4]2– and Sr-centred nine-fold polyhedra SrO6(OH)3. The B–O–OH polyanion is the cluster of three tetrahedra and three triangles; these clusters are decorated by the [B2O2(OH)3] pyro-group consisting of two triangles. The layers are linked via vertices of Sr-centred polyhedra, which share seven vertices with B-centred polyhedra of one layer and two vertices with B-centred polyhedra of the adjacent layer, and by the system of H bonds. The crystal chemistry of strontioborite is discussed in comparison with other natural and synthetic borates.

Fragment of the phase diagram of the Cu-CrSe2 system at room temperature

The chemical and electrochemical extraction of copper from CuCrSe2 was carried out at room temperature (RT). The compositions corresponding to the boundaries of the homogeneity region of CuyCrSe2 and Cu1-xCrSe2 were determined. X-ray diffraction (XRD) analysis demonstrated that within the composition range of y from 0 to 0.29, the phase with the structure of CrSe2 with space group P3¯m1 is stable. Furthermore, within the composition range of x from 0 to 0.33, the phase with the structure of delafossite CuCrSe2 (space group R3m) is stable.

Synthesis, characterization, X-ray structure, and DFT calculations of Zn complex encompassing HLN2O ligand: Relevance in cytotoxicity and antifungal photodynamic therapy.

This article presents the synthesis, characterization, and X-ray crystallographic features of one new Zn complex derived from a Salen-type tridentate ligand (HLN2O). A single-crystal diffraction study determined the complex crystal structure, which confirms that it crystallizes in the orthorhombic space group P212121. The single-crystal structure is constructed using the unique mononuclear component [ZnLN2°] and supramolecular CH∙∙∙π type interaction, resulting in a 1D structure. The IR, HRMS, and NMR study also support the complex structure. The Zn metal centre has a distorted square pyramidal geometry with τ value of 0.49. The Hirshfeld surfaces and 2D fingerprint confirm predominant H…H (77.9 %) interactions, with minor H…O, H…C, and H…N (5.0 %, 4.9 %, and 0.2 %). DFT calculations employed the B3LYP-D3/Lanl2DZ class of theory. FMO/MEP explains the complex reactivity perspective, while IP (4.71 eV) and low EA (1.11 eV) suit biological applications. The bonding gateway was analysed using NBO/QTAIM-NCI and ELF-LOL plots. Cytotoxicity was assessed using the Trypan blue exclusion method and tested against the DLA cell line, showing effectiveness against the DLA cell and suggesting complex potential as an anticancer agent. Antifungal photodynamic therapy (APDT) explored that ligand and Zn complex have significant activity against C. albicans. Finally, molecular docking simulations substantiate the experimental findings.

Protonated oxalyl chloride and the ClCO+ cation.

The reactions of oxalyl chloride were investigated in the binary superacidic systems HF/SbF5 and DF/SbF5. O-Monoprotonated oxalyl chloride was isolated and represents the first example of a protonated acyl chloride. Diprotonated oxalyl chloride is only stable in solution. Salts of the ClCO+ cation were synthesized from the reactions of oxalyl chloride or COClF with SbF5 in 1,1,1,2-tetrafluoroethane (R-134a, CF3CFH2). The colourless salts were characterized by low-temperature vibrational spectroscopy, NMR spectroscopy and single-crystal X-ray diffraction. (1,2-Dichloro-2-oxoethylidene)oxidanium hexafluoridoantimonate(V), [C2O(OH)Cl2][SbF6], crystallizes in the monoclinic space group P21 and carbonyl chloride hexadecafluoridotriarsenate(V) [ClCO][Sb3F16], in the trigonal space group P31, with two and three formula units per unit cell, respectively. Monoprotonated oxalyl chloride and the ClCO+ cation both display very short C-Cl bonds with a strong double-bond character.

Interfacing inorganic halide perovskites with metal-organic frameworks: Color tunable emission, energy transfer, and advanced anti-counterfeiting application

This work presents an inorganic halide perovskite (CsPbBr3) is interfaced with a europium metal-organic framework (Eu-MOF). The presence of characteristic absorption edge and band edge emission of CsPbBr3 reveal a successful formation of CsPbBr3@Eu-MOF hybrid. The bi-flower morphology of Eu-MOF has tetragonal structure with space group P4322. The conical part of the bi-flower consists of many squared rods of edge length 200 nm. The CsPbBr3@Eu-MOF shows color-tunable emission under different excitation wavelengths whose CIE color coordinate covers the entire green to red region. The maximum luminous efficacy of the optical radiation achieved is 359 lm/W, and the maximum color purity is 94.4 %, which is significant for optical applications. Further for anti-counterfeiting application, a pattern “LMDD” is encrypted on four different substrates and the color change is captured under different excitation wavelengths. The results show that CsPbBr3@Eu-MOF is highly suitable for encryption and decryption of security codes particularly on plastic surface.

The stannides SrPdSn and m-BaPtSn

Abstract The stannides SrPdSn (TiNiSi type, orthorhombic space group Pnma) and m-BaPtSn (EuNiGe type, monoclinic space group P21/c) were synthesized from the elements in sealed tantalum ampoules in a high-frequency furnace. Their structures were refined from single-crystal X-ray diffraction data. SrPdSn crystallizes directly from the melt and is stable upon annealing at T = 1073 K. A BaPtSn sample quenched from the melt adopts the cubic LaIrSi-type structure, cubic space group P213 (c-BaPtSn) and shows a temperature induced (annealing at 1070 K) structural phase transition leading to a EuNiGe-type low-temperature modification m-BaPtSn. The phase transition leads to a reconstruction within the polyanionic [PtSn] δ− network. The latter is three-dimensional and composed of ten-membered Pt5Sn5 rings in c-BaPtSn, while the polyanion is two-dimensional in m-BaPtSn and is composed of condensed Pt4Sn4 and Pt2Sn2 rings. The two-dimensional substructure leads to a strong moisture sensitivity for m-BaPtSn. The Pt–Sn distances in both modifications range from 257 to 267 pm, indicating substantial covalent bonding.

Noncollinear Magnetic Structures in the Chiral Antiperovskite β-Fe2SeO.

We present the magnetic properties of the chiral, polar, and possibly magnetoelectric antiperovskite β-Fe2SeO as derived from magnetization and specific-heat measurements as well as from powder neutron diffraction and Mössbauer experiments. Our macroscopic data unambiguously reveal two magnetic phase transitions at TN1 ≈ 103 K and TN2 ≈ 78 K, while Rietveld analysis of neutron powder diffraction data reveals a noncollinear antiferromagnetic structure featuring magnetic moments in the a-b plane of the trigonal structure and a ferromagnetic moment along c. The latter is allowed by symmetry between TN1 and TN2, weakly visible in the magnetization data yet unresolvable microscopically. While the intermediate phase can be expressed in the trigonal magnetic space group P31, the magnetic ground state is modulated by a propagation vector q = (1/2 1/2 0) resulting in triclinic symmetry and an even more complex low-temperature spin arrangement which is also reflected in the Mössbauer hyperfine patterns indicating additional splitting of Fe sites below TN2. The complex noncollinear spin arrangements suggest interesting magnetoelectric properties of this polar magnet.

Synthesis, crystal structure, Hirshfeld surface analyses and antibacterial activity of 2-fluorobenzylpyridinium tetrabromidocuprate(II)

In this article, novel organic-inorganic hybrid material, 2-fluorobenzylpyridinium tetrabromidocuprate(II) [2FBzPy]2[CuBr4], has been obtained by using a slow evaporation solution-growth method and was characterized by powder X-ray diffraction, infrared spectroscopy, scanning electron microscopy, UV–visible diffuse reflectance spectrum. The compound crystallizes in the monoclinic space group P21 /c, and the packing is governed by C − H···Br hydrogen bonding interactions, which was confirmed by the Hirshfeld surface analysis. The results of antimicrobial experiments showed that the compound possessed excellent antimicrobial activity against Staphylococcus aureus and Escherichia coli. RESEARCH HIGHLIGHTS An inorganic-organic hybrid salt [2FBzPy]2[CuBr4] was synthesized and characterized. The main intermolecular interaction in [2FBzPy]2[CuBr4] crystals have been studied and analyzed. The interactions between different molecules in[2FBzPy]2 [CuBr4] were examined by Hirshfeld surface analyses. [2FBzPy]2[CuBr4] had an optical band gap of 1.69 eV, was a typical semiconductor material with good optical property. The as-synthesized salts exhibits good antibacterial activities against S. aureus and E. coli.

Intermolecular Interactions in Molecular Ferroelectric Zinc Complexes of Cinchonine

The use of chiral organic ligands as linkers and metal ion nodes with specific coordination geometry is an effective strategy for creating homochiral structures with potential ferroelectric properties. Natural Cinchona alkaloids, e.g., quinine and cinchonine, as compounds with a polar quinuclidine fragment and aromatic quinoline ring, are suitable candidates for the construction of molecular ferroelectrics. In this work, the compounds [CnZnCl3]·MeOH and [CnZnBr3]·MeOH, which crystallize in the ferroelectric polar space group P21, were prepared by reacting the cinchoninium cation (Cn) with zinc(II) chloride or zinc(II) bromide. The structure of [CnZnBr3]·MeOH was determined from single-crystal X-ray diffraction analysis and was isostructural with the previously reported chloride analog [CnZnCl3]·MeOH. The compounds were characterized by infrared spectroscopy, and their thermal stability was determined by thermogravimetric analysis and temperature-modulated powder X-ray diffraction experiments. The intermolecular interactions of the different cinchoninium halogenometalate complexes were evaluated and compared.

Synthesis and structural characterization of a new colchicine monosquarate-amide derivative

Colchicine is a compound isolated from Colchicum autumnale, which is characterized by high anticancer activity. A new amide derivative of colchicine with a squaric acid ester skeleton has been synthesized by the reaction between deacetylated thiocolchicine and diethyl ester of squaric acid. The synthesis under optimized reaction conditions gave the desired product (colchicine monosquarate-amidoester - 5) in the excellent yield of 90%. This compound crystallizes in the non-centrosymmetric space group P21 of the monoclinic system as dihydrate (5‧2H2O) which was confirmed by the X-ray analysis of the single crystal at room temperature. As the temperature decreases to 100 K, the crystal partially loses water that was also confirmed by X-ray single crystal analysis. The obtained amidoester 5 has been analyzed by NMR (1D and 2D), FT-IR and ESI-MS spectroscopy. At room temperature the 1H and 13C NMR spectra showed doubling of signals, which suggested that in the solution, the product existed as rotamers. This hypothesis was confirmed using variable–temperature (VT) 1H NMR and 13C NMR spectroscopies.

Strong Antiferromagnetic Interactions in the Binuclear Cobalt(II) Complex with a Bridged Nitroxide Diradical

A binuclear cobalt–radical complex formed by the reaction of Co(hfac)2·2H2O (hfac = hexafluoroacetylacetonate) with the 2,2-bis(1-oxyl-3-oxide-4,4,5,5-tetramethylimidazolinyl) biradical (BR) has been synthesized. The complex {(hfac)CoII(BN)CoII(hfac)} crystallizes in the triclinic space group P1¯ : C34H28Co2F24N4O12, a = 11.1513(5) Å, b = 12.8362(7) Å, c = 18.2903(8) Å, α = 103.061(1)°, β = 100.898(2)°, γ = 102.250(1)°, Z = 2. The compound consists of two non-equivalent pseudo-octahedral CoII ions, each bearing two hfac ancillary ligands bridged by the tetradentate bis-nitroxide (BN). The temperature dependence of the magnetic susceptibility indicates a strong antiferromagnetic exchange between each of the Co2+ ions and the nitroxyl biradical, as well as between the spins within the bridging ligand, forming a spin-frustrated system. Micro-squid investigations, performed on a single crystal of {(hfac)CoII(BN)CoII(hfac)}, reveal a peculiarity of the M(H) graph at temperatures below 0.4 K displaying a step that is a result of ground and first excited levels mixing by the applied magnetic field due to a small energy gap between them, as inferred from ab initio calculation. The latter was also carried out for two models of mononuclear Co2+ complexes in order to obtain a set of initial parameters for fitting the experimental magnetic curves using the Phi program. Moreover, direct CAS(12,10)/def2-TZVP calculations of the magnetic dependences χT(T) and M(H) were performed, which satisfactorily reproduced the experimental ones.

Novel Strategy of Treating 2-Nitrobenzoic Acid Crystals with Energetic N2 Neutrals Using Cold Plasma

The organic adduct compounds of 2-nitrobenzoic acid crystals were grown as optically transparent crystals using the conventional slow evaporation solution technique. The crystals were powdered and irradiated with cold plasma. Cell parameter analysis confirmed the formation of a new crystalline material that resides in the triclinic P crystal system with space group P1. Fourier transform infrared spectra were recorded using the KBr pellet technique to determine the vibrational functional groups in the compound. Powder X-ray diffraction analysis was used to reveal the crystalline orientation of the powdered samples of the grown crystals. The obtained full width at half maximum for the (001) plane in the XRD spectrum indicates the excellent crystalline quality of the 2-nitrobenzoic acid crystals. The recorded UV–Vis absorption spectra reveal that the grown powdered crystal samples possess cut-off edges wavelengths at 428 and 428 nm and 353 and 354 nm for pure and plasma-treated samples, respectively. The optical energy bandgaps were found to be 2.0, 2.25, 4.06, and 4.02 eV for the pure and plasma-treated samples, respectively. The photoluminescence spectra show the blue emissions of the crystal. The FE-SEM images show the morphological modifications in which rounded platelets appear on the surfaces of the treated crystals.

Crystals of para-quaterphenyl and its trimethylsilyl derivative. I. Growth from solutions, structure and crystal chemical analysis by the Hirschfeld surface method

The results of crystal growth of para-quaterphenyl (4P) and its derivative – 4,4''-bis(trimethylsilyl)-para-quaterphenyl (TMS-4P-TMS) from solutions are presented. It has been established that TMS-4P-TMS crystals exhibit better growth characteristics compared to 4P. Parameters of phase transitions of 4P and TMS-4P-TMS in closed crucibles were refined using the method of differential scanning calorimetry. The crystal structure of TMS-4P-TMS in the triclinic space group P1 (Z = 2) has been decrypted for the first time using single-crystal X-ray diffraction and studied over a wide temperature range. Crystallographic analysis of the studied compounds in crystals was performed using the Hirshfeld surface method, and modeling of intermolecular interactions was conducted.

Dissymmetrization in eudialyte-group minerals. I. A model of ordered cation arrangement in the crystal structure of amableite-(Ce) using the P3 symmetry

The crystal structure of the recently discovered eudialyte group mineral, amabellite-(Ce) Na15[(Ce1.5Na1.5)Mn3]Mn2Zr3£Si[Si24O69(OH)3](OH)2 · H2O, found in the hyperagpaitic pegmatite of the Saint-Amable massif (Canada), has been solved by X-ray structural analysis within the space group R3. Amabellite-(Ce) is a member of the eudialyte group with the lowest calcium content and differs from other members of this group by the dominance of lanthanides in the part of the edge-sharing octahedra of the six-membered ring. The unit cell parameters of the mineral are: a = 14.1340(2), c = 30.378(1) Å, V = 5255.6(3) ų. A model of the cation distribution in the crystal structure of amabellite-(Ce) within the low-symmetry space group P3 has been proposed. The obtained 162 independent positions were refined in the isotropic-anisotropic approximation of atomic displacements using 3968 F 3σ(F), R = 4.6%. Despite the fairly close results, the transition from space group R3 to P3 allows for more detailed information on the local distribution of a number of elements over the framework positions. A comparison was made between the crystal structure models of amabellite within the symmetries R3 and P3, as well as other low-calcium eudialyte group minerals previously studied within several space groups.

Structural and theoretical insights into the influence of thiocyanate ligands on divalent metal complexes with terpyridine derivatives

Four complexes with terpyridine derivative, thiocyanate anion, and selected d-electron metals were studied. The obtained complexes of the formulation [M(ftpy)(SCN)2(CH3OH)]•DMF (M = Mn (1), Co (2), Ni (3)) and [Cu(ftpy)(NCS)2]•H2O (4), where ftpy = 4′‐(furan-2-yl)-2,2′:6′,2′′‐terpyridine, were characterized using FTIR and UV–Vis spectroscopies, magnetic studies, elemental analysis, and single crystal X-ray crystallography. All compounds crystallize in a triclinic crystal system with space group P1¯ and 1–3 are isomorphous and isostructural. The effect of the modification of the terpyridine ligand and the presence of the thiocyanate ligand on the structure has been verified. Interesting dependence was found in the structure of compound 4, where the two thiocyanate ligands are differently coordinated, one via N and the other via S, and the formation of complex dimers connected through hydrogen bonds is observed. The π-stacking interactions and the resulting solid-state architectures of compounds 1–4 were inspected through a combination of DFT calculations, QTAIM, and NCIPlot analyses, and the stability of the complexes was studied by UV–Vis spectroscopy in various solvents.

The crystal structure of R3Fe0.1Ga1.6S7 chalcogenides (R – La, Ce, Pr and Tb)

The paper reports the study of the crystal structure of chalcogenides of the composition R3Fe0.1Ga1.6S7 (R = La, Ce, Pr and Tb) as promising materials predicted to possess interesting nonlinear optical and electrical properties. Samples of stoichiometric composition were synthesized by co-melting the elements in quartz containers evacuated to a residual pressure of 10–2 Pa at the maximum synthesis temperature of 1100 °C. The crystal structure of the chalcogenides La3Fe0.1Ga1.6S7 {a = 10.1884(6) Å, c = 6.0515(4) Å}, Ce3Fe0.1Ga1.6S7 {a = 10.0864(4) Å, c = 6.0440(3) Å}, Pr3Fe0.1Ga1.6S7 {a = 9.9853(3) Å, c = 6.0648(2) Å} and Tb3Fe0.1Ga1.6S7 {a = 9.6692(7) Å, c = 6.0799(5) Å} was studied by X-ray powder method. It was determined that the structure of the synthesized phases belongs to the hexagonal symmetry (La3CuSiS7 structure type; space group P63). The structure of the complex chalcogenides (A), (B), (C) and (D) is based on the R3Ga1.67S7 sulfides (R = La, Ce, Pr, and Tb) by substituting gallium atoms in the 2a sites with atoms of statistical mixture M1{0.57(2) Ga + 0.10(2) Fe}, M2{0.56(1) Ga + 0.10(2) Fe}, M3 {0.61(8) Ga + 0.09(1) Fe} and M4 {0.57(2) Ga + 0.10(2) Fe}, respectively. Rare earth atoms are localized in the 6c sites and center sulfur atoms to form trigonal prisms with an additional atom [R 3S13S21S3]. Atoms of statistical mixtures M1, M2, M3, M4 are localized in the 2a sites forming [M 6S2] octahedra. Ga atoms in the 2b sites are surrounded by four sulfur atoms [Ga 3S11S3].

Features of the Structure and Thermal Properties of LnBWO6 (La = Ln, La0.999Nd0.001, La0.99Gd0.01) Synthesized by the Sol-Gel Method

Borate tungstates LnBWO6 (Ln = La, La0.999Nd0.001, La0.99Gd0.01) were synthesized by the Pechini method with subsequent annealing of intermediates. They were analyzed by X-ray diffraction (XRD) and DSC methods. Crystallographic parameters of synthesized LnBWO6 were refined by powder X-ray diffraction in two systems: monoclinic, space group P21, and orthorhombic, space group P222. The presence of reversible first-order phase transitions in synthesized LnBWO6 was detected using the DSC method, and the temperatures and enthalpies of phase transformations were determined. It has been shown that Nd3+ and Gd3+ dopants lowers the L- → H- phase transition temperature of LaBWO6. According to experimental electron paramagnetic resonance (EPR) data gadolinium has two independent positions in the La0.99Gd0.01BWO6 structure.

Influence of cation disorder on the mineral physics of ankerite

Abstract The structural evolution and compressibility of ordered and disordered ankerite at pressures up to ~25 GPa using synchrotron single crystal X-ray diffraction in diamond anvil cell was analyzed. Ordered ankerite (space group R3) undergoes discontinuous phase transition between 12.15 and 13.45 GPa to a high-pressure structure called ankerite-II (space group P1) that has Ca in eight-fold coordination. Disordered ankerite (R3c space group) does not undergo a phase transition in the investigated pressure range. A Birch-Murnaghan equation of state has been used to fit the volume compressibility. Ordered ankerite [K0V=95(1) GPa - K’=3.8(3)] appears slightly more compressible than disordered ankerite [K0V=99(1) GPa - K’=2.7(1)]. The phase transition in ordered ankerite has a change in volume of approximately 0.6% and K13.45V=110(11) GPa - K’=7(3) for ankerite-II. The possible significance of this differential behavior of ordered and disordered ankerite is discussed.

Neutral water-soluble µ-S nitrosyl iron complex with acetylcysteine non-silent in EPR spectra

The water-soluble neutral binuclear nitrosyl iron complex with N-acetyl-L-cysteine was synthesized. As follows from X-ray analysis, the complex crystallizes in the monoclinic crystal system, space group P2(1). The distance between iron atoms is 2.7 Å The complex belongs to Roussin's red salt esters (RRE) and is expected to be diamagnetic. However, in the EPR-spectrum there is a broad line with a g-factor of 2.010, which disappears upon the dissolution of the complex in water or alcohol. However, dissolution of the complex in DMSO leads to an increase in the classical signal for mononuclear nitrosyl iron complex with a g-factor of 2.03. The IR-spectrum of the crystalline sample of the complex shows an atypical pattern among RREs. This behaviour was studied with quantum-chemical calculations. The magnetic properties of the complex are also unusual for a complex of this structural type. The complex was also studied by Mössbauer and UV-spectroscopy.