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The iron(III) anionic complex based on a pyruvic acid thiosemicarbazone ligand with the lithium cation Li[Fe III (thpy) 2 ]·3H 2 O (1) has been synthesized and characterized by FTIR spectroscopy, powder and single crystal X-ray diffraction, direct current magnetic susceptibility measurements, and 57 Fe Mössbauer spectroscopy. Moreover, the molecular structure of the [Fe(thpy) 2 ] - anion has been determined for the first time. The [Fe(thpy) 2 ] - units in the triclinic P 1̄ lattice of 1 are assembled into layers parallel to the bc plane. The Li + cations and water molecules are located between the layers and the structure is stabilized by hydrogen bonding. The [Fe(thpy) 2 ] - anions form interconnected dimer pairs through hydrogen bonds and short contacts with Fe⋯Fe separation of 6.7861(4) Å. According to dc magnetic measurements, compound 1 demonstrates an incipient spin-crossover transition from the LS ( S = 1/2) to the HS ( S = 5/2) state above 250 K. The Bleaney-Bowers equation for a model of an isolated LS dimer with a mean-field correction was applied to fit the experimental data of magnetic susceptibility dependence on temperature in the temperature range of 2-250 K. The intra-dimer J 1 = -1.79(1) K and inter-dimer J 2 = -0.24(3) K antiferromagnetic coupling constants were defined. The analysis of the 57 Fe Mössbauer spectra at 80 K and 296 K confirms the presence of the shortened distances between the iron nuclei. Moreover, the influence of the lithium cation on the stabilization of the LS state was shown for the [Fe(thpy) 2 ] - anion. BS-DFT calculations for the optimized structure of two isolated [Fe(thpy) 2 ] - anions also correctly predict a weak exchange J 1 (calc) = -0.92 K. DFT calculations revealed the OPBE (GGA-type) functional that correctly predicts the spin-crossover transition for the iron(III) thpy compounds. Besides, the effect of the N 2 O 4 , N 2 S 2 O 2 , and N 2 Se 2 O 2 coordination environments on the energy stabilization of the LS state of iron(III) anionic thpy complexes was noted as well.

Four new heterometallic complexes combining [M II (H 2 dapsc)] 2+ cations with the chelating H 2 dapsc {2,6-diacetylpyridine-bis(semicarbazone)} Schiff base ligand and [Cr(CN) 6 ] 3- anion were synthesized: {[M II (H 2 dapsc)]Cr III (CN) 6 K(H 2 O) 2.5 (EtOH) 0.5 } n ·1.2 n (H 2 O), M = Mn ( 1 ) and Co ( 2 ), {[Mn(H 2 dapsc)] 2 Cr(CN) 6 (H 2 O) 2 }Cl·H 2 O ( 3 ) and {[Co(H 2 dapsc)] 2 Cr(CN) 6 (H 2 O) 2 }Cl·2EtOH·3H 2 O ( 4 ). In all the compounds, M(II) centers are seven-coordinated by N 3 O 2 atoms of H 2 dapsc in the equatorial plane and N or O atoms of two apical -CN/water ligands. Crystals 1 and 2 are isostructural and contain infinite negatively charged chains of alternating [M II (H 2 dapsc)] 2+ and [Cr III (CN) 6 ] 3- units linked by CN-bridges. Compounds 3 and 4 consist of centrosymmetric positively charged trimers in which two [M II (H 2 dapsc)] 2+ cations are bound through one [Cr III (CN) 6 ] 3- anion. All structures are regulated by π-stacking of coplanar H 2 dapsc moieties as well as by an extensive net of hydrogen bonding. Adjacent chains in 1 and 2 interact also by coordination bonds via a pair of K + ions. The compounds containing Mn II ( 1 , 3 ) and Co II ( 2 , 4 ) show a significant difference in magnetic properties. The ac magnetic measurements revealed that complexes 1 and 3 behave as a spin glass and a field-induced single-molecule magnet, respectively, while 2 and 4 do not exhibit slow magnetic relaxation in zero and non-zero dc fields. The relationship between magnetic properties and non-covalent interactions in the structures 1 - 4 was traced.

Three tetraphenylborates of mononuclear Mn(III) cation complexes with hexadentate ligands, the products of the reaction between a N,N'-bis(3-aminopropyl)ethylenediamine and salicylaldehydes with the different haloid substitutions at the 5 or 3,5 positions, have been synthesized: [Mn(5-F-sal-N-1,5,8,12)]BPh 4 (1), [Mn(3,5-diCl-sal-N-1,5,8,12)]BPh 4 (2) and [Mn(3,5-Br,Cl-sal-N-1,5,8,12)]BPh 4 (3). Their crystal structure, dielectric constant (ϵ) and magnetic properties have been studied. Ligand substituents have a dramatic effect on the structure and magnetic properties of the complexes. With decreasing temperature, the complex (1) shows a gradual spin crossover from the high-spin state (HS) to the HS:LS intermediate phase, followed by an abrupt transition to the low-spin state (LS) without changing the crystal symmetry. The complexes 2 and 3 are isostructural, but have fundamentally different properties. Complex 2 demonstrates two structural phase transitions related to sharp spin crossovers from the HS to the HS:LS intermediate phase at 137 K and from the intermediate phase to the LS at 87 K, while complex 3 exhibits only one spin transition from the HS to the HS:LS intermediate phase at 83 K., (© 2021 Wiley-VCH GmbH.)

A potassium salt of the N 2 S 2 O 2 -coordination Fe(III) anion K[Fe(5Cl-thsa) 2 ] ( 1 ) (5Cl-thsa - 5-chlorosalicylaldehyde thiosemicarbazone) is synthesized and characterized structurally and magnetically over a wide temperature range. Two polymorphs of salt 1 characterized by the common 2D polymer nature and assigned to the same orthorhombic Pbcn space group have been identified. The molecular structure of the minor polymorph of 1 was solved and refined at 100, 250, and 300 K is shown to correspond to the LS configuration. The dominant polymorph of 1 features K + cations disordered over a few crystallographic sites, while the minor polymorph includes fully ordered K + cations. The major polymorph exhibits a complete three-step cooperative spin-crossover transition both in the heating and cooling modes: The first step occurs in a temperature range from 2 to 50 K; the second abrupt hysteretic step occurs from 200 to 250 K with T 1/2 = 230 K and a 6 K hysteresis loop. The third gradual step occurs from 250 to 440 K. According to 57 Fe Mössbauer, XRPD, and EXAFS data, the spin-crossover transition for the dominant polymorph is quite peculiar. Indeed, the increase in the HS concentration by 57% at the second step does not result in the expected significant increase in the iron(III)-ligand bond lengths. In addition, the final step of the spin conversion (Δγ HS = 26%) is associated with a structural phase transition with a symmetry lowering from the orthorhombic ( Pbcn ) to the monoclinic ( P 2 1 / n ) space group. This nontrivial phenomenon was investigated in detail by applying magnetization measurements, electron spin resonance, 57 Fe Mössbauer spectroscopy, and DFT calculations. These results provide a new platform for understanding the multistep spin-crossover character in the Fe(III) thsa-complexes and related compounds.

A series of six seven-coordinate pentagonal-bipyramidal (PBP) erbium complexes, with acyclic pentadentate [ N 3 O 2 ] Schiff-base ligands, 2,6-diacetylpyridine bis-(4-methoxybenzoylhydrazone) [H 2 DAPMBH], or 2,6-diacethylpyridine bis(salicylhydrazone) [H 4 DAPS], and various apical ligands in different charge states were synthesized: [Er(DAPMBH)(C 2 H 5 OH)Cl] ( 1 ); [Er(DAPMBH)(H 2 O)Cl]·2C 2 H 5 OH ( 2 ); [Er(DAPMBH)(CH 3 OH)Cl] ( 3 ); [Er(DAPMBH)(CH 3 OH)(N 3 )] ( 4 ); [(Et 3 H)N] + [Er(H 2 DAPS)Cl 2 ] - ( 5 ); and [(Et 3 H)N] + [Y 0 . 95 Er 0 . 05 (H 2 DAPS)Cl 2 ] - ( 6 ). The physicochemical properties, crystal structures, and the DC and AC magnetic properties of 1 - 6 were studied. The AC magnetic measurements revealed that most of Compounds 1 - 6 are field-induced single-molecule magnets, with estimated magnetization energy barriers, U eff ≈ 16-28 K. The experimental study of the magnetic properties was complemented by theoretical analysis based on ab initio and crystal field calculations. An experimental and theoretical study of the magnetism of 1 - 6 shows the subtle impact of the type and charge state of the axial ligands on the SMM properties of these complexes.

Metal complexes of trithiadodecaazahexaphyrin (Hhp) that contain M II 3 O clusters inside a π-extended trianionic (Hhp 3- ) macrocycle have been prepared. Studies of the magnetic properties of Ni II 3 O(Hhp) and Cu II 3 O(Hhp) reveal a diamagnetic and EPR-silent trianionic (Hhp 3- ) macrocycle and diamagnetic Ni II 3 (O 2- ) or paramagnetic Cu II 3 (O 2- ) tetracations. The positive charge of M II 3 O(Hhp) is compensated by one acetate anion {M II 3 O(Hhp)} + (CH 3 CO 2 - ). The three-electron reduction of {M II 3 O(Hhp)} + yields {cryptand(Cs + )} 2 {Ni II 2 Ni I O(Hhp 5- )} 2- ·2C 7 H 8 ( 1 ) and {cryptand(Cs + )} 2 {Cu II 3 O(Hhp •6- )} 2- ·C 7 H 8 ( 2 ) crystalline salts. The magnetic properties of 1 reveal the formation of Hhp 5- and the reduction of nickel(II) to the paramagnetic Ni I ion ( S = 1/2), which is accompanied by the formation of the {Ni II 2 Ni I O(Hhp 5- )} 2- dianion. As a result, the magnetic moment of 1 is 1.68 μ B in the 20-220 K range, and a broad EPR signal of Ni I was observed. The Hhp 5- macrocycle has a singlet ground state, but the increase in the magnitude of the magnetic moment of 1 above 220 K is attributed to the population of the triplet excited state in Hhp 5- . The {Ni II 2 Ni I O(Hhp 5- )} 2- dianion is transferred from the doublet excited state to the quartet excited state with an energy gap of 1420 ± 50 K. Salt 1 also shows an unusually strong low-energy NIR absorption, which was observed at 1000-2200 nm. In 2 , a highly reduced Hhp •6- radical hexaanion ( S = 1/2) coexists with a Cu II 3 (O 2- ) cluster ( S = 1/2) in the {Cu II 3 O(Hhp •6- )} 2- dianions. The dianions have a triplet ground state with antiferromagnetic exchange between two S = 1/2 spins with J = -6.4 cm -1 . The reduction of Hhp in both salts equalizes the initially alternated C-N bonds, supporting the increase in the Hhp macrocycle electron delocalization.

A series of three mononuclear pentagonal-bipyramidal V(iii) complexes with the equatorial pentadentate N3O2 ligand (2,6-diacethylpyridinebis(benzoylhydrazone), H2DAPBH) in the different charge states (H2DAPBH0, HDAPBH1-, DAPBH2-) and various apical ligands (Cl-, CH3OH, SCN-) were synthesized and characterized structurally and magnetically: [V(H2DAPBH)Cl2]Cl·C2H5OH (1), [V(HDAPBH)(NCS)2]·0.5CH3CN·0.5CH3OH (2) and [V(DAPBH)(CH3OH)2]Cl·CH3OH (3). All three complexes reveal paramagnetic behavior, resulting from isolated S = 1 spins with positive zero-field splitting energy expected for the high-spin ground state of the V3+ (3d2) ion in a PBP coordination. Detailed high-field EPR measurements for compound 3 show that its magnetic properties are best described by using the spin Hamiltonian with the positive ZFS energy (D = +4.1 cm-1) and pronounced dimer-like antiferromagnetic spin coupling (J = -1.1 cm-1). Theoretical analysis based on superexchange calculations reveals that the long-range spin coupling between distant V3+ ions (8.65 Å) is mediated through π-stacking contacts between the planar DAPBH2- ligands of two neighboring [V(DAPBH)(CH3OH)2]+ complexes.

In this study, crystals of the hybrid layered structure, combined with Fe(III) Spin-Crossover (SCO) complexes with metal-dithiolate anionic radicals, and the precursors with nitrate and iodine counterions, are obtained and characterized. [Fe(III)(3-OMe-Sal 2 trien)][Ni(dmit) 2 ] ( 1 ), [Fe(III)(3-OMe-Sal 2 trien)]NO 3 ·H 2 O ( 2 ), [Fe(III)(3-OMe-Sal 2 trien)]I ( 3 ) (3-OMe-Sal 2 trien = hexadentate N 4 O 2 Schiff base is the product of the condensation of triethylenetetramine with 3-methoxysalicylaldehyde; H 2 dmit = 2-thioxo-1,3-dithiole-4,5-dithiol). Bulk SCO transition was not achieved in the range 2.0-350 K for all three compounds. Alternatively, the hybrid system ( 1 ) exhibited irreversible segregation into the spatial fractions of Low-Spin (LS) and High-Spin (HS) phases of the ferric moiety, induced by thermal cycling. Fractioning was studied using both SQUID and EPR methods. Magnetic properties of the LS and HS phases were analyzed in the framework of cooperative interactions with anionic sublattice: Anion radical layers Ni(dmit) 2 ( 1 ), and H-bonded chains with NO 3 and I ( 2 , 3 ). LS phase of ( 1 ) exhibited unusual quasi-two-dimensional conductivity related to the Arrhenius mechanism in the anion radical layers, ρ ||c = 2 × 10 5 Ohm·cm and ρ ⟂c = 7 × 10 2 Ohm·cm at 293 K. Ground spin state of the insulating HS phase was distinctive by ferromagnetically coupled spin pairs of HS Fe 3+ , S = 5/2, and metal-dithiolate radicals, S = 1/2.

A series of compounds with Sc 3 N@I h -C 80 in the neutral, monomeric, and dimeric anion states have been prepared in the crystalline form and their molecular structures and optical and magnetic properties have been studied. The neutral Sc 3 N@I h -C 80 ⋅3 C 6 H 4 Cl 2 (1) and (Sc 3 N@I h -C 80 ) 3 (TPC) 2 ⋅5 C 6 H 4 Cl 2 (2, TPC=triptycene) compounds both crystallized in a high-symmetry trigonal structure. The reduction of Sc 3 N@I h -C 80 to the radical anion resulted in dimerization to form diamagnetic singly bonded (Sc 3 N@I h -C 80 - ) 2 dimers. In contrast to {[2.2.2]cryptand(Na + )} 2 (Sc 3 N@I h -C 80 - ) 2 ⋅2.5 C 6 H 4 Cl 2 (3) with strongly disordered components, we synthesized new dimeric phases {[2.2.2]cryptand- (K + )} 2 (Sc 3 N@I h -C 80 - ) 2 ⋅2 C 6 H 4 Cl 2 (4) and {[2.2.2]cryptand- (Cs + )} 2 (Sc 3 N@I h -C 80 - ) 2 ⋅2 C 6 H 4 Cl 2 (5) in which only one major dimer orientation was found. The thermal stability of the (Sc 3 N@I h -C 80 - ) 2 dimers was studied by EPR analysis of 3 to show their dissociation in the 400-460 K range producing monomeric Sc 3 N@I h -C 80 .- radical anions. This species shows an EPR signal with a hyperfine splitting of 5.8 mT. The energy of the intercage C-C bond was estimated to be 234±7 kJ mol -1 , the highest value among negatively charged fullerene dimers. The EPR spectra of crystalline (Bu 3 MeP + ) 3 (Sc 3 N@I h -C 80 .- ) 3 ⋅C 6 H 4 Cl 2 (6) are presented for the first time. The salt shows an asymmetric EPR signal, which could be fitted by three lines. Two lines were attributed to Sc 3 N@I h -C 80 .- . Hyperfine splitting is manifested above 180 K due to the hyperfine interaction of the electron spin with the three scandium atoms (a total of 22 lines with an average splitting of 5.32 mT are observed at 220 K). Furthermore, each of the 22 lines is additionally split into six lines with an average separation of 0.82 mT. The large splitting indicates intrinsic charge and spin density transfer from the fullerene cage to the Sc 3 N cluster. Both the monomeric and dimeric Sc 3 N@I h -C 80 - anions show an intrinsic shift of the IR bands attributed to the Sc 3 N cluster and new bands corresponding to these species appear in the NIR range of their UV/Vis/NIR spectra, which allows these anions to be distinguished from neutral species., (© 2019 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Reactions of [Mn(H 2 dapsc)Cl 2 ]⋅H 2 O (dapsc=2,6- diacetylpyridine bis(semicarbazone)) with K 3 [Fe(CN) 6 ] and (PPh 4 ) 3 [Fe(CN) 6 ] lead to the formation of the chain polymeric complex {[Mn(H 2 dapsc)][Fe(CN) 6 ][K(H 2 O) 3.5 ]} n ⋅1.5n H 2 O (1) and the discrete pentanuclear complex {[Mn(H 2 dapsc)] 3 [Fe(CN) 6 ] 2 (H 2 O) 2 }⋅4 CH 3 OH⋅3.4 H 2 O (2), respectively. In the crystal structure of 1 the high-spin [Mn II (H 2 dapsc)] 2+ cations and low-spin hexacyanoferrate(III) anions are assembled into alternating heterometallic cyano-bridged chains. The K + ions are located between the chains and are coordinated by oxygen atoms of the H 2 dapsc ligand and water molecules. The magnetic structure of 1 is built from ferrimagnetic chains, which are antiferromagnetically coupled. The complex exhibits metamagnetism and frequency-dependent ac magnetic susceptibility, indicating single-chain magnetic behavior with a Mydosh-parameter φ=0.12 and an effective energy barrier (U eff /k B ) of 36.0 K with τ 0 =2.34×10 -11  s for the spin relaxation. Detailed theoretical analysis showed highly anisotropic intra-chain spin coupling between [Fe III (CN) 6 ] 3- and [Mn II (H 2 dapsc)] 2+ units resulting from orbital degeneracy and unquenched orbital momentum of [Fe III (CN) 6 ] 3- complexes. The origin of the metamagnetic transition is discussed in terms of strong magnetic anisotropy and weak AF interchain spin coupling., (© 2019 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)

The iron(iii) complex [Fe(Hsemsal)(semsal)]·3H2O (1) (H2semsal - salicylaldehyde semicarbazone) has been synthesized and characterized by powder and single crystal X-ray diffraction, and magnetic susceptibility measurements. Crystal structure analysis showed that the complex forms neat stacks stabilized by hydrogen-bonding through water molecules and π-π interactions between phenolate rings of ligands. The complex does not exhibit spin-crossover phenomena and remains in the high-spin state down to 2 K. DFT calculations were performed for a series of neutral Fe(iii) complexes, and the influence of the N2S2O2, N2Se2O2 and N2O4 coordination environment on the spin transition in these complexes was traced. The effect of substituents in the benzene ring of salicylaldehyde on the stabilization of the HS or LS states in complexes of this type was analyzed.

A diamagnetic complex, {(cis-indigo-N,N) 2- (Cp*Ir III )} (1), in which deprotonated cis-indigo dianions coordinate an iridium center through two nitrogen atoms was obtained. By employment of the ability of the iridium center in 1 to coordinate an additional ligand, the complex [(Bu 4 N + ) 2 {[Sn II (Pc •3- )](cis-indigo-N,N) 2- Cp*Ir III } •- 2 ·0.5(H 2 Indigo)·2.5C 6 H 4 C l2 (2), which has two functional ligands coordinating an Ir III center, was obtained. This complex has a magnetic moment of 1.71 μ B at 300 K, in accordance with an S = 1/2 spin state. The spin density is mainly delocalized over the Pc •3- macrocycle and partially on (cis-indigo-N,N) 2- . Due to an effective π-π interaction, a thermally activated charge transfer from [Sn II (Pc •3- )] •- to (cis-indigo-N,N) 2- is observed, with an estimated Gibbs energy (-ΔG°) of 9.27 ± 0.18 kJ/mol. The deprotonation of indigo associated with the coordination of Ir III by the indigo releases H + ions, which protonate noncoordinating indigo molecules to produce leuco cis-indigo (H 2 Indigo). One H 2 indigo links two (cis-indigo-N,N) 2- dianions in 2 to produce strong N-H···O═C and O-H···O═C hydrogen-bonding interactions.

Two one-dimensional cyano-bridged coordination polymers, namely, {[Mn II (dapsc)][Mn III (CN) 6 ][K(H 2 O) 2.75 (MeOH) 0.5 ]} n ·0.5n(H 2 O) (I) and {[Mn II (dapsc)][Mn III (CN) 6 ][K(H 2 O) 2 (MeOH) 2 ]} n (II), based on alternating high-spin Mn II (dapsc) (dapsc = 2,6-diacetylpyridine bis(semicarbazone)) complexes and low-spin orbitally degenerate hexacyanomanganate(III) complexes were synthesized and characterized structurally and magnetically. Static and dynamic magnetic measurements reveal a single-chain magnet (SCM) behavior of I with an energy barrier of U eff ≈ 40 K. Magnetic properties of I are analyzed in detail in terms of a microscopic theory. It is shown that compound I refers to a peculiar case of SCM that does not fall into the usual Ising and Heisenberg limits due to unconventional character of the Mn III -CN-Mn II spin coupling resulting from a nonmagnetic singlet ground state of orbitally degenerate complexes [Mn III (CN) 6 ] 3- . The prospects of [Mn III (CN) 6 ] 3- complex as magnetically anisotropic molecular building block for engineering molecular magnets are critically analyzed.

Reduction of scandium nitride clusterfullerene, Sc3N@Ih-C80, by sodium fluorenone ketyl in the presence of cryptand[2,2,2] allows the crystallization of the {cryptand[2,2,2](Na(+))}2(Sc3N@Ih-C80(-))2·2.5C6H4Cl2 (1) salt. The Sc3N@Ih-C80˙(-) radical anions are dimerized to form single-bonded (Sc3N@Ih-C80(-))2 dimers.

The radical anion salt [Fe{HC(pz)3}2](TCNQ)3 demonstrates conductivity and spin-crossover (SCO) transition associated with Fe(II) complex cation subsystem. It was synthesized and structurally characterized at temperatures 100, 300, 400, and 450 K. The compound demonstrates unusual for 7,7,8,8,-tetracyanoquinodimethane (TCNQ)-based salts quasi-two-dimensional conductivity. Pronounced changes of the in-plane direct-current resistivity and intensity of the electron paramagnetic resonance (EPR) signal, originated from TCNQ subsystem, precede the SCO transition at the midpoint T* = 445 K. The boltzmannian growth of the total magnetic response and structural changes in the vicinity of T* uniquely show that half [Fe{HC(pz)3}2] cations exist in high-spin state. Robust broadening of the EPR signal triggered by the SCO transition is interpreted in terms of cross relaxation between the TCNQ and Fe(II) spin subsystems.

Ionic compounds containing radical anions of metal-free phthalocyanine (H2Pc˙(-)): (H2Pc˙(-))(cryptand[2,2,2][Na(+)])·1.5C6H4Cl2 (1) and (H2Pc˙(-))(TOA(+))·C6H4Cl2 (2) have been obtained as single crystals for the first time. Their crystal structures have been determined, and optical and magnetic properties have been investigated. The H2Pc˙(-) radical anions have a slightly bowl-like shape with four pyrrole nitrogen atoms located below the molecular plane, while four phenylene substituents are located above this plane. Changes in the average length of N-C and C-C bonds in H2Pc˙(-) in comparison with those in neutral H2Pc indicate that negative charge is mainly delocalized over the 24-atom phthalocyanine ring rather than the phenylene substituents. The H2Pc˙(-) formation is accompanied by a shift of up to 10 cm(-1) and disappearance of some intense IR-active bands whereas the band of the N-H stretching mode is shifted by 21-27 cm(-1) to larger wavenumbers. New bands attributed to H2Pc˙(-) appear in the NIR spectra of the salts with maxima at 1033 and 1028 nm for 1 and 2, respectively. The formation of H2Pc˙(-) is accompanied by the splitting of the Soret and Q-bands of H2Pc into several bands and their blue-shift up to 32 nm. Narrow EPR signals with g = 2.0033 and linewidth of 0.16-0.24 mT at room temperature in the spectra of the salts were attributed to the H2Pc˙(-) radical anions. According to SQUID measurements they have S = 1/2 spin states with effective magnetic moments of 1.73 (1) and 1.78 (2) μB at 300 K. Magnetic behavior of 1 and 2 follows the Curie-Weiss law with negative Weiss temperatures of -0.9 and -0.5 K, respectively, indicating weak antiferromagnetic interactions of spins. The EPR signal splits into two lines below 120 and 80 K for 1 and 2, respectively and these lines are noticeably broadened below 25 K.

A new high symmetry Mn(12) oxocarboxylate cluster [Mn(12)O(12)(CN-o-C(6)H(4)CO(2))(12)(CH(3)CO(2))(4)(H(2)O)(4)]·8CH(2)Cl(2) (1) with mixed carboxylate ligands is reported. It was synthesized by the standard carboxylate substitution method. 1 crystallizes in the tetragonal space group I4(1)/a. Complex 1 contains a [Mn(12)O(12)] core with eight CN-o-C(6)H(4)CO(2) ligands in the axial positions, four CH(3)CO(2) and four CN-o-C(6)H(4)CO(2) in equatorial positions. Four H(2)O molecules are bonded to four Mn atoms in an alternating up, down, up, down arrangement indicating a 1 : 1 : 1 : 1 isomer. The Mn(12) molecules in 1 are self-assembled by complementary hydrogen C-H···N bonds formed with participation of the axial o-cyanobenzoate ligands of the adjacent Mn(12) clusters. The lattice solvent molecules (CH(2)Cl(2)) are weakly interacted with Mn(12) units that results in solvent loss immediately after removal of the crystals from the mother liquor. The electronic structure and the intramolecular exchange parameters have been calculated. Mn 3d bands of 1 are rather broad, and the center of gravity of the bands shifts down from the Fermi level. The overlap between Mn 3d bands and 2p ones of the oxygen atoms from the carboxylate bridges is higher than in the parent Mn(12)-acetate cluster. These changes in the electronic structure provide a significant difference in the exchange interactions in comparison to Mn(12)-acetate. The magnetic properties have been studied on a dried (solvent-free) polycrystalline sample of 1. The dc magnetic susceptibility measurements in the 2-300 K temperature range support a high-spin ground state (S = 10). A bifurcation of temperature dependencies of magnetization taken under zero field cooled and field cooled conditions observed below 4.5 K is due to slow magnetization relaxation. Magnetization versus applied dc field exhibited a stepwise hysteresis loop at 2 K. The ac magnetic susceptibility data revealed the frequency dependent out-of-phase (χ(M)'') signals characteristic of single-molecule magnets.

Ionic complexes containing μ(2)-hydroxo-bonded (MgPc)(2)OH(-) phthalocyanine assemblies and C(60)(-) anions: {(MgPc)(2)OH(-)}(2)·(C(60)(-))(2)·(PMDAE(+))(4)·(C(6)H(5)CN)(4) (1); {(MgPc)(2)OH(-)}(2)·(C(60)(-))(2)·(TMP(+))(4)·(C(6)H(5)CN)(3)·(C(6)H(4)Cl(2))(2.5) (2) (where PMDAE(+) is the cation of N,N,N',N',N'-pentamethyldiaminoethane and TMP(+) is the N,N'N'-trimethylpiperazinium cation) have been obtained as single crystals. The ionic ground state of the complexes is justified by the EPR spectra and the spectra in the IR and NIR ranges. The C(60)˙(-) radical anions are dimerized both in 1 and 2 in the 240-220 K range. Dimerization is accompanied by the reversible transition of the complexes from paramagnetic to diamagnetic state. MgPc forms unusual (MgPc)(2)OH(-) assemblies, in which the hydroxo-anion coordinates to two MgPc molecules by a μ(2)-fashion. The length of the Mg-O bonds is 1.936-1.955(2) Å, the Mg-O-Mg angle is 133.37-135.27(4)° and the displacement of the Mg atoms out of the mean 24-atom phthalocyanine plane is 0.77-0.86 Å. The packing of spherical fullerene and planar phthalocyanine molecules is attained in a crystal by the insertion of fullerenes between phenylene groups of phthalocyanines. It has been shown that metal phthalocyanines in ionic complexes with C(60) form M(II)Pc·(L(-)) assemblies, whereas metalloporphyrins form M(II)porphyrin·(C(+)) assemblies.

Ionic complexes containing C(60)(*-) radical anions and metalloporphyrins coordinatively bound to N,N',N'-trimethylpiperazinium cations {(TMP(+))(2).M(II)TPP}.(C(60)(-))(2).(C(6)H(4)Cl(2))(2).(C(6)H(5)CN)(2) [M = Zn (1) and Mn (2)] have been obtained. The crystal structures of 1 and 2 solved at 250 and 270 K, respectively, show layered packing in which fullerene layers alternate with the (TMP(+))(2).M(II)TPP ones. Fullerenes form pairs in the layer with short center-to-center distances of 10.044 and 10.077 A, respectively. The structures of 1 and 2 solved at 100 K indicate the formation of singly bonded (C(60)(-))(2) dimers. That results in the transition of 1 from the paramagnetic to diamagnetic state accompanied by the disappearance of the electron paramagnetic resonance (EPR) signal of C(60)(*-) at 220-150 K. Dimerization in 2 results in a decrease in the magnetic moment from 6.36 to 6.00 mu(B) at 200-150 K and a change in the shape of EPR signal. The room-temperature EPR signal shows a major broad component at g = 2.0678 (DeltaH = 111.6 mT) attributed to both paramagnetic C(60)(*-) and high-spin (TMP(+))(2).Mn(II)TPP species having strong exchange interaction. After dimerization, the signal is characteristic of isolated high-spin Mn(II)TPP (g( perpendicular) = 6 with |A| = 7.3 mT and g(||) approximately 2). Two TMP(+) cations can coordinate to M(II) in (TMP(+))(2).M(II)TPP. However, a weak coordination bond is formed only with one cation with the M(II)...N(TMP(+)) distances of 2.489(2)-2.688(3) A. As a result, metal atoms displace by +/-0.232(3) A (1, 250 K), +/-0.231(1) A (1, 100 K) and +/-0.4684(7) A (2, 270 K) out of the porphyrin plane to be located above and below the porphyrin plane with equal occupancies for both positions. The symmetry of the crystal structure of 2 decreases from monoclinic to triclinic under cooling. That results in unequal 0.85/0.15 occupation of the Mn(II) positions at 100 K with displacement of the metal by 0.391(2) and 0.554(4) A, respectively.

Complementary shapes of the neutral symmetrical halogen-bond bis-donor core and octahedral inorganic cluster core prevent halogen-bonded polymers developing in more than one direction, favouring further templating by conducting radical cation slabs and yielding an 8 : 1 : 1 phase formulation instead of n : 2 : 1, with a 2D net, or m : 3 : 1, with a pseudo-cubic architecture, which may in principle also be targeted.