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The crystals of a perylene complex with the polymeric cluster containing [Mn6O2(O2CCHCl2)10(H2O)2] units assembled by 3,10-perylenequinone bridges, {[Mn6O2(O2CCHCl2)10(H2O)2(C20H10O2)]2n·(C20H12)n} (I), were obtained in the reaction of [Mn12O12(O2CCHCl2)16(H2O)4] with perylene. Unlike the Mn12 oxodichloroacetate cluster, the reaction of the Mn12 oxobenzoate cluster, [Mn12O12(O2CPh)16(H2O)4], with perylene does not occur. However, it turned out that the crystals isolated from the reaction are a new Mn12 oxobenzoate cluster containing three molecules of coordinated H2O and solvate molecules of hexane, [Mn12O12(O2CC6H5)16(H2O)3]·2C6H12 (II). Crystal structures of complexes I and II as well as the magnetic properties of the former were studied.

The reactions of [Mn4(hmp)6(NO3)2(H2O)2](ClO4)2 with (Bu4N)2[CoX4] (X = Cl, Br) in CH3CN have been studied and the new heterometallic tetranuclear clusters [CoIII2MnII2(hmp)6Cl2(CH3CN)2]MnIICl4·3CH3CN and [CoIII2MnII2(hmp)6Br2(CH3CN)2]MnIIBr4·4CH3CN have been synthesized and characterized by TGA, electrospray ionization mass spectrometry, single-crystal X-ray diffraction, and magnetic measurements. The magnetic properties of the heterometallic clusters were analyzed by DFT and ab initio calculations.

The new Mn12 magnetic clusters with 4-cyanobenzenecarboxylate ligand, [Mn12O12(O2CC6H4-p-CN)16(H2O)4] (1) and its singly (2) and doubly (3) reduced analogues as their tetraphenylphosphonium salts, ...

The bis(μ-alkoxo)-bridged dinuclear iron(III) complex, [Fe2(hmp)2Cl4] (I), [hmp = 2-hydroxymethylpyridine] was synthesized by reaction of the [Mn4(hmp)6(NO3)2(H2O)2](ClO4)2 with (Et4N)[FeCl4] under conditions of slow diffusion of starting reagents into solvent and characterized by single crystal X-ray diffraction and variable-temperature magnetic susceptibility measurements. The iron centers have a mixed-ligand five-fold coordination (O2NCl2) with a distorted trigonal bipyramidal geometry. Two Fe(III) ions are bridged by the oxygen atoms from two hmp ligands, with Fe ⋅ ⋅ ⋅ Fe distance of 3.158(1) A and Fe-O-Fe bridge angle 107.37(7)°. Magnetic studies in the temperature range 300–4.2 K indicated a moderately strong intramolecular antiferromagnetic coupling between the high-spin Fe(III) ions with J = − 38.5 cm− 1.

X-ray single crystal diffraction study of the new molecular conductor (TSeF)7[FeNO(CN)5]2 has been carried out at room temperature and 130 K. The crystal structure is composed by layers of π-electron donors TSeF, separated by anion layers along the a-direction. The conducting organic layer has unusual for molecular conductors arrangement of neutral monomeric and charged hexameric TSeF units orthogonally packed with respect to each other. Another specific feature of the structure is fully ordered state of the nitroprusside anion and deep penetrating of its functional NO-group into the adjacent organic layer.

The first heterometallic chain cluster {[Mn4(hmp)6(NO3)2FeNO(CN)5·4CH3CN}n (1) based on the [Mn4(hmp)6] SMM has been synthesized. 1 has one-dimensional chain structure: the [Mn4(hmp)6] units are linked via CN-groups of nitroprusside anions. Its magnetic and relaxation properties and low temperature IR spectra under light irradiation have been investigated. The ferromagnetic exchange constants have been calculated.

Mono- and dianionic oxocarboxylate Ru-Mn12 clusters, [RuNO(en)2Cl]-[Mn12O12(O2CR)16(H2O)4]2 (R = Ph (1)), [RuNO(en)2Cl][Mn12O12(O2CR)16(H2O)4] (R = C6F5 (2), CH2Cl (3), R = CHCl2 (4)), and [RuNO(NH3)4OH][Mn12O12(O2CR)16(H2O)4] (R = CH2Cl (5), CHCl2 (6)) containing photochromic mononitrosyl ruthenium complexes as cations were synthesized. The magnetic properties of the complexes in static and alternating magnetic fields were studied, and compounds 1–6 were found to be molecular nanomagnets. By IR spectroscopy, they were shown to exhibit also photochromic properties.

Two bifunctional supramolecular systems [RuNO(NH 3 ) 4 OH] 2+ · [RuNO(NH 3 ) 4 H 2 O] 3+ Cd 3+ (H 2 O) 6 · 2[TCAS] 4- · 4H 2 O (1) and [RuNO(NH 3 )4OH] 2+ · [RuNO(NH 3 ) 4 H 2 O] 3+ · Dy 3+ (H 2 O) 6 · 2[TCAS] 4- · 4H 2 O (2) on the platform of p-sulfonatothiacalix[4]arene containing photochromic mononitrosyl Ru and paramagnetic rare-earth (Cd 3+ , Dy 3+ ) cations have been synthesized. The crystal structures of 1 and 2 are discussed. Their photochromic, magnetic and photomagnetic properties studied by IR and SQUID experimental techniques are presented.

The magnetic properties of new bifunctional molecular magnets based on nitrosyl complexes of ruthenium and thiacalix[4]arenes of rare-earth ions (Gd3+, Dy3+) have been investigated. A photoinduced decrease in the magnetization of the molecular magnet with rare-earth ions Gd3+ and the absence of a photomagnetic effect in crystals with rare-earth ions Dy3+ have been revealed at a temperature of 2 K. It has been found that, in the sample containing Dy3+ ions, the magnetization deviates by 6% from the calculated value for noninteracting ions. A comparison of the results obtained for two groups of isostructural samples, which differ only in the type of rare-earth ions, has demonstrated that the observed deviation of the magnetization is caused by the interaction of the orbital moment of the Dy3+ ions with the crystal field.

Two metastable nitrosyl linkage isomers SI and SII are generated by light irradiation in the spectral range 370–500 nm in the two diamagnetic compounds [RuNO(NH 3 ) 5 ][Co(CN) 6 ] and [RuNO(NH 3 ) 5 ] 2 [ZrF 6 ] 3 as well as in the paramagnetic compound [RuNO(NH 3 ) 5 ][Cr(CN) 6 ]. The frequencies of the ν (NO) stretching vibrations of SI and SII identify SI as the isonitrosyl Ru–O–N isomer and SII as the side-on η 2 isomer of NO. The population, i.e., the number of generated linkage isomers, is determined from the decrease of the area of the fundamental ν (NO) and of the higher harmonic 2 · ν (NO) of the ν (NO) stretching vibration of the ground state. Using differential scanning calorimetry (DSC) the heat release during the thermal decay of the metastable linkage isomers is determined. The activation energies, frequency factors, and the energetic position of the metastable linkage isomers are determined from the DSC and infrared spectroscopic experiments. It is found that the exchange of the counter ion significantly influences the energetic positions of the linkage isomers, while the activation energy and frequency factor are much less affected.

Four new radical cation salts based on the amide functionalized EDT-TTF organic donors EDT-TTF-CONH 2 (D1) and EDT-TTF-(CONH 2 ) 2 (D2), α′-(D1) 4 [FeNO(CN) 5 ] ( 1 ), α′-(D1) 4 [Co(CN) 6 ] ( 2 ), β-(D1) 6 [Fe(CN) 6 ] ( 3 ) and (D2) 4 [FeNO(CN) 5 ]NB ( 4 ), have been synthesized and characterized by X-ray single crystal diffraction experiments, band structure calculations and electrical resistivity measurements. Functionalized organic donors are remarkable for the ability to form cation⋯cation and cation⋯anion type hydrogen bonds which can effectively direct the crystal architecture of molecular conductors. The structural analysis reveals a well-developed hydrogen bond network in the crystals investigated. (D1) 2 -dimers or (D2) n -extended zigzag chains of donors connected through functional groups are found to be stable structural motifs in 1 – 4 . Remarkably, salts 1 and 2 are isostructural despite the presence of anions of different charge (−2 and −3, respectively) and the inherent difference in the degree of charge transfer has a clear effect on the transport properties: σ RT ( 2 )/ σ RT ( 1 ) = 300. Salt 3 differs from 1 and 2 both in the stoichiometry and packing of the conducting organic layer. Crystals of 4 exhibit a superstructure with the incommensurate vector q = ±(0.5, 0.3, 0.2).

International audience; The radical cation salts based on BDH-TTP and the mono- and diamide functionalized derivatives of EDT-TTF with the double charged nitroprusside anion [FeNO(CN)5]2- (NP): kappa -(BDH-TTP)4[NP]C6H5NO2 (1), kappa -(BDH-TTP)4[NP] (2), (BDH-TTP)2[NP] (3), alpha-[ EDT-TTF-CONH 2]4[NP] (4), beta -[ EDT-TTF-(CONH2)2]2[NP] 0.5(C6H5NO2)0.5 (5) have been synthesized. The crystal structures and transport properties of 1 - 5, as well as electronic band structures of 1and 2 have been studied.

The synthesis of a series of novel compounds containing the photochromic mononitrosyl cation [Ru(NH 3 ) 5 NO] 3+ and metal complex paramagnetic anions : [Ru(NH 3 ) 5 NO] [M(CN) 6 ] (M= Cr (1), Fe (2)), [Ru(NH 3 ) 5 NO][Cr(CN) 5 NO] (3), [Ru(NH 3 ) 5 NO][M(ox) 3 ] (M=Cr (4), Fe (5)) is reported. The crystal structure of salt 1 is discussed. The magnetic properties of 1 and 4 compounds studied by EPR and SQUID experimental techniques are presented.

The crystals of (BEDT-TTF)4K[Fe(CN)5NO]2, representing a quasi-two-dimensional organic metal with conducting layers of bis(ethylenedithio)tetrathiofulvalene (BEDT-TTF) and nonconducting layers containing pho-tochromic nitroprusside anions [Fe(CN)5NO]2−, were studied by the method of electron spin resonance. Illuminated by light with a wavelength of 514.5 nm, the organic metal crystals feature the formation of localized paramagnetic centers in the conducting cation layers of BEDT-TTF. The phenomenon of electron localization in the BEDT-TTF layers is related to the light-induced formation of long-lived metastable states of nitroprusside anions.

A single crystal X-ray diffraction (XRD) study of the radical cation salt (EDT-TTF) 3 [Fe(CN) 5 NO] has been carried out ( a =6.623(3), b =10.487(2), c =15.951(1) A, α =109.19(1), β =96.30(2), γ =99.15(3)°, V =1017.3(5) A 3 , space group P 1, Z =1). The crystals have a layered structure with the distinctive feature of the presence of alternating EDT-TTF dimers and monomers in the radical cation stacks. Both the structural features and the calculated HOMO⋯HOMO interaction energies suggest that the strong intradimer interaction is responsible for the charge separation and the semiconducting properties of the salt.

Radical cation salts of tetrathiotetracene (TTT) and tetraselenotetracene (TSeT) with photochromic anion [Fe(NO)(CN)5]2– having the compositions (TTT)3[Fe(NO)(CN)5] (I) and (TSeT)3[Fe(NO)(CN)5] (II) were synthesized. Their crystal structures and conducting and optical properties were studied. The salt structures are featured by stacks of TTT or TSeT triads. Analysis of the bond lengths in TTT and TSeT revealed localization of a charge in the triads, where one molecule is neutral and the other two molecules are charged (1+). At room temperature, the conductivity of crystals I and II along the stack direction is 6 × 10–2 and 5–7 Ohm–1 cm–1, respectively. Unlike I, the temperature dependence of conductivity of II has peculiarities at 285 and 160 K due to phase transitions. The transition at 160 K was discovered also in the reflection spectra.

(BEDO-TTF)4[Fe(CN)5NO] was synthesized by electrocrystallization using the nitroprussides M2[Fe(CN)5NO]·2H2O (M = K, Rb) as supporting electrolytes and TCE (1,1,2-trichloroethane) and DCE (1,2-dichloroethane) as solvents. The crystal structure of this new salt (a = 4.0251(3), b = 15.266(2), c = 19.259(2) A, α = 97.02(1), β = 93.23(1), γ = 96.04(1)°, V = 1165.1(2) A3, Z = 3/4, space group P) is characterized by the presence of β″-type radical cation layers and anion layers containing disordered nitroprusside anions. The stoichiometry was confirmed by a micro-Raman spectroscopic study and the band structure and Fermi surface of this new salt were studied by means of the extended Huckel tight binding method. (BEDO-TTF)4[Fe(CN)5NO] is a two dimensional metal stable down to liquid helium temperatures.

Tight-binding band structure calculations for the room temperature crystal structure of the new family of (BEDT-TTF)4M[Fe(CN)5NO]2 (M=Na, K, Rb, NH4, Cs, Tl) salts are reported. It is shown that the Fermi surface of these salts contains two contributions: (a) a strongly warped non-nested open part and (b) a contribution which can be open or closed depending on minor changes in the donor–donor interactions which in either case exhibits well-nested portions. Because of these features, the pressure dependence of both the magnetoresistance measurements and the possible occurrence of density wave instabilities would be very interesting to study.

A series of electroconducting radical cation salts based on ET, BEDO and EDT with the photochromic nitroprusside anion has been synthesized. Their crystal structures and transport properties have been studied. The salts of the (ET) 4 M[Fe(CN) 5 NO] 2 (M=Na,K,NH 4 ,Tl,Rb,Cs) composition are isostructural and exhibit metallic behaviour down to helium temperatures.

We present the results of spectral studies of Et 4 N[Au(dmit) 2 TCNQ] salt containing alternating stacks of Au(dmit)2 and TCNQ molecules. The polarized transmission spectra of single crystals are measured in the IR region (650 to 6500 cm -1 ) as a function of temperature (90 to 300 K). Moreover, the powder absorption spectra in the frequency range (400 to 40000 cm -1 ) are reported. From spectral evidence results that transferred electrons are localized on Au(dmit)2 molecules in the mixed stacks. The intrastack charge transfer between Au(dmit)2 and TCNQ molecules (∼ 8000 cm -1 ) and the interstack charge transfer transition between Au(dmit) 2 molecules (∼ 5500 cm -1 ) are found. Interactions of electrons with intramolecular vibrations of TCNQ (a g modes) and Au(dmit)2 (C = C and C = S stretching) are suggested and discussed.

The synthesis, crystal and electronic band structures as well as conducting properties of the new stable molecular metal [Pd(dddt) 2 ]Ag 1.54 Br 3.50 (dddt = 5,6-dihydro-1,4-dithiin-2,3-dithiolato) are reported. The crystal structure contains layers of donor cations alternating with layers of silver bromide complex anions along the a axis of the unit cell. The Ag and Br atoms are disordered in the anion layer. The conducting layers contain uniform stacks of the translationally equivalent Pd(dddt)2 cations along the c-axis with a Pd... Pd distance of 4.157(2) A. Within the cation layers there are shortened interstack S...S contacts (3.49(3) and 3.56(3) A). The temperature dependence of the resistivity exhibits metallic behaviour down to 1.3 K. The resistivity anisotropy (p a * Pbc) at room temperature is about 600 and does not change considerably when decreasing the temperature down to 4.2 K. The origin of the metallic conductivity of [Pd(dddt) 2 ]Ag 1.54 Br 3.50 as well as the stability of this salt with respect to metal-to-insulator transitions is explained on the basis of tight binding band structure calculations.

As a part of our general approach in the study of new hybrid molecular materials combining conducting properties with other physical phenomena, we analyze crystal structures and properties of radical cation salts with the photochromic metal mononitrosyl complexes and magnetic metal oxalates as counterions. A detailed comparative crystallochemical analysis of such materials coupled with calculation of their electronic band structures should allow us to conceive a scenario for the rational search of novel hybrid functional materials.

The structure and conductivity of the Me 4 N[Au(dmit) 2 ] 2 crystals obtained have been studied. Structures and conducting properties of analogous M(dmit) 2 anion complexes with M = Au, Ni and Pd have been compared.

A series of highly conducting salts based on Au (III) complexes with dmit have been synthesized. The crystal structures and conducting properties have been studied. A new type of the M( dmit ) 2 salts containing mixed anion [Au( dmit ) 2 TCNQ] − have been obtained.

A new radical cation salt based on the dithiolate complex Pd(dddt)2 (dddt=5,6-dihydro-1,4-dithiine-2,3-dithiolate) with the tetrahedral anion [GaBr4]− was synthesized. The crystal and molecular structure was determined by XRD analysis. The crystal structure of the salt contains Pd(dddt)2 cation layers alternating with layers of [GaBr4]− anions along thec axis of the unit cell. The cation layers contain stacks of Pd(dddt)2, with a Pd...Pd distance of 3.011 A. The electroconductivity of [Pd(dddt)2]2GaBr4, single crystals at room temperature is 0.25 Ohm−1 cm−1 and decreases with temperature decrease, the activation energy beingEa=0.66 eV.

An X-ray structural investigation of a new molecular semiconductor. [Pd(dddt) 2 ] 2 CF 3 SO 3 (1), where dddt 2- is 5,6-dihydro-1,4-dithiin-2,3-dithiolate, is made. Crystal data of 1: a = 6.521(7) A, b = 8.354(4) A, c = 16.113(6 ) A, α = 87.12(4)°, β = 85.51(6)°, γ = 67.94(7)°, V = 811(1) A 3 , triclinic, space group P1. Crystal structure 1 is characterized by layers of [Pd(dddt) 2 ] 1/2+ radical cations, with [CF 3 SO 3 ] - anions located between them. In these layers, [Pd(dddt) 2 ] 1/2+ cations form dimers with strongly shortened intermolecular contacts Pd...Pd 3.031(2) A. The [CF 3 SO 3 ] - anion in the structure of 1 is disordered.

A series of electroconducting cationic salts based on the Pd(dddt) 2 and Ni(dddt) 2 complexes has been synthesized. The first stable molecular metals have been found among the M(dddt) 2 salt family.

The reaction of the [Mn12O12(O2CCHCl2)16(H2O)4] cluster with tetrathiotetracene triiodide has been studied and, for the first time, reduction fragmentation of Mn12 cluster to Mn6 cluster has been found.

Summary form only given. The M(dddt)/sub 2/ complexes (dddt2- = 5,6-dihydro-1,4dithiin-2,3 dithio late) arouse great interest for they are isolobal analogs of the molecule BEDT-TTF [1] which is known to form superconducting cation radical salts [2]. In this work the first cation salts of Pd(dddt)/sub 2/ with the anions different in their geometry and electronic configuration (IBr/sub 2/, C10/sub 4/, ZnC1O/sub 4/, PF/sub 6/, SnC1/sub 6/ etc) were prepared by electrochemical oxidation of Pd(dddt)/sub 2/ neutral complex. Some of them were found to be molecular metals. Properties and structure of Pd(dddt)/sub 2/ cation salts were compared with those of BEDT-TTF and Pt(dddt)/sub 2/ ones. In contrast to the latters with the octahedral doubly charged anions, which are dielectric at Low temperatures, Pd(dddt)/sub 2/ salt with TeC1/sub 6//sup 2-/ has high conductivity at 4.2 K (20 /spl Omega//sup -1/cm/sup -1/).

Polarized reflectance spectra from single crystals and powder absorption spectra of (ET) 2 C(CN) 3 salt are measured in the middle IR region. The metal-insulator phase transition influences the IR spectra especially within the range of C  C vibrations. The strong coupling of electrons with v 27 (b 1u ) mode (antisymmetric stretching of C  C ring bonds) is observed.

Infrared spectra of [Ni(dddt) 2 ] 3 (HSO 4 ) and [Pd(dddt) 2 ] 2 X (X=TeCl 6 , AuBr 2 ) are measured at room temperature. Moreover, FT-NIR-Raman spectrum of [Ni(dddt) 2 ] 2 (HSO 4 ) 2 is reported. Electronic and vibrational bands are discussed. The strong coupling of electrons with vibrations of C=C ring bonds of M(dddt) 2 cations is observed.

θ-(BETS)4[Fe(CN)5NO] (1), (BETS)2[RuBr5NO] (2), and (BETS)2[RuCl5NO] (3) [BETS = bis(ethylenedithio)tetraselenafulvalene] have been prepared by electrocrystallisation of BETS using [Fe(CN)5NO]2− or [RuX5NO]2−, X = Cl or Br, as supporting electrolytes and 1,1,2-TCE/ethanol (10 vol%) for 1, nitrobenzene/1,2-DCE (40 vol%)/ethanol (10 vol%) for 2, and benzonitrile/ethanol (10%) solutions for 3 as solvents. Compound 1 exhibits a metallic behaviour down to 40 K, 2 behaves as a semiconductor and 3 as an insulator. The crystal structures of 1, 2, and 3 were determined by X-ray diffraction methods. BETS molecules in 1 crystallised in a θ-type mode. By contrast, the crystal structures of 2 and 3 show a packing of BETS molecules consisting of slipped, stacked (BETS)2 dimers. The dimerisation is much stronger in 3 than in 2. The physical behaviours of the three phases were investigated by means of molecular and band structure calculations and are shown to be directly related to the [MX5NO] (M = Fe, X = CN; M = Ru, X = Cl, Br) structural conformations.

Polarized IR reflectance and transmittance spectra of [Pd(dddt) 2 ] 2 SbF 6 single crystals are measured in the frequency range 650 to 6500 cm −1 as a function of temperature (90 to 300 K). A phase transition at T=200 K influences both electronic and vibrational bands.

1. Mixed halides of tetraselenotetracene (TSeT) TSeT2BrxCl1−x were obtained as monocrystals and the value for x in these compounds is a function of the ratio of the oxidizing agents CuBr2/CuCl2 used in the preparation of the complexes. 2. An x-ray fluorescence method was deveoped for the analysis of Cl and Br when both these halides are present in samples with high selenium content. 3. The low-temperature metal-semimetal transition is washed out in mixed TSeT halides as x → 0.5, the temperature maximum for the conductivity is shifted toward higher temperatures, and a decreases relative to pure TSeT chloride and bromide. 4. A phase transition to a new metallic state is found under pressure in mixed TSeT halides which is retained in the entire temperature range from 300‡ to 1.3‡K. The pressure for the transition is a function of the ratio of Br− and Cl− anions in the complexes.

We present the results of studies of the polarized reflectance spectra in the frequency region from 650 cm-1 to 40 000cm-1 of [Pd(dddt)2]Ag1.54Br3.50 single crystals at room temperature. The reflectance in the middle IR range is analysed using a Drude model. Assuming a tight-binding band suitable transfer integrals are determined. The electronic band structure is discussed.