The structural, magnetic, hydrogenation and electrode properties of REMg2Cu9?xNix alloys (RE=La, Pr,Tb)

The LaMg₂Cu₉, PrMg₂Cu₉, LaMg₂Cu₄Ni₅, PrMg₂Cu₄Ni₅ and TbMg₂Cu₆Ni₃ alloys were prepared for the investigations of crystal structure, magnetic and hydrogen storage properties. The magnetic properties of several REMg₂Cu_9−xNi_x compounds have been studied up to 9 T and from 2 to 300 K. Tb compounds show a ferrimagnetic (with Ni) or antiferromagnetic (without Ni) behaviour, which can be attributed to the Tb magnetic structure. At high temperature a paramagnetic Curie Weiss behaviour is observed and the effective moment corresponds to that of Tb. A magnetic contribution of Pr moment is observed in both Pr compounds, with larger magnetization for PrMg₂Cu₄Ni₅ and a transition at 3 K. The hydrogen absorption occurs at 95 bar for LaMg₂Cu₉ (3 H f.u.⁻¹) and above 2 bars for LaMg₂Cu₄Ni₅ (1.6 H f.u.⁻¹). The effect of Cu-Ni substitution on the electrochemical properties of LaMg₂M₉ ternary alloys was investigated leading to maximum discharge capacity of 250–310 mAh g⁻¹.      

Ion association studies in aqueous NiSO4 solutions by positron lifetime spectroscopy

Ion association has been studied by positron lifetime spectroscopy in aqueous solutions containing the Ni²⁺ and SO ₄ ^2– ions at 294 K with the double aim of assessing the reliability of the method for quantitative determination of complex formation constants and of probing the validity of various expressions to calculate single-ion activity coefficients at high ionic strength. The existence of two complexes, identified as NiSO₄ and Ni₂SO ₄ ²⁺ , is shown by the data analysis. Considering the formation constant of the former, K_I=(196±10)M^–1, determined in previous works leads to discarding several of the expressions commonly used for activity corrections. Two possible values are retained for K_I, (193±20)M^–1 and (179±20)M^–1, while K_II related to Ni₂SO ₄ ²⁺ is better defined, as (2.57±0.14)M^–1.     

Iron- and nickel-containing oxide-phosphate layers on aluminum and titanium

Oxide-phosphate surface structures with thicknesses of 5 to 50 μm containing iron and nickel compounds have been synthesized by plasma electrolysis (PE) in aqueous electrolytes with polyphosphate nickel(II) and iron(III) complexes. The elemental and phase compositions have been studied as affected by polarization parameters, electrolytes, and annealing parameters. Simple and complex oxides and phosphates crystallize in layers: on aluminum, AlPO₄, NiAl₂O₄, and Fe₂O₃ crystallize; on titanium, Ni₂P₂O₇, Ni_0.5TiOPO₄, NaTi₂(PO₄)₃, M^(II)M^(III)Ti(PO₄)₃, FePO₄, and Fe₂Fe(P₂O₇)₂ crystallize.     

Electronic absorption spectra of M2L6 compounds containing metal-metal triple bonds of σ2π4 configuration

The electronic absorption spectra of compounds containing metal-metal triple bonds of σ²π⁴ valence electronic configuration are presented and discussed. The lowest-energy transition of M₂L₆ compounds (M = Mo or W, L = CH₂Bu^t or OBu^t) is expected to be the dipole-allowed π → π* (e_u → e_g) transition. This appears to be the case for M₂(CH₂Bu^t)₆ and M₂(OBu^t)₆ compounds, in which the lowest energy absorption bands occur between 26,000 and 28,000 cm⁻¹ (ε = 1.1 x 10³-1.8 x 10³ M⁻¹ cm⁻¹). For M₂(NMe₂)₆ compounds, the lowest energy absorption is not the π → π* transition but is assigned instead to a LMCT transition originating from nitrogen lone-pair orbitals, N_1p → π*, observed at 30,800 cm⁻¹ (ε = 1.4 x 10⁴-1.9 x 10⁴ M⁻¹ cm⁻¹). The π → π* transition is not observed in these compounds, but is presumably masked by the more intense LMCT. These assignments are derived from Xα-SW calculations performed and described by other authors (Bursten et al., J. Am. Chem. Soc. 1980, 102, 4579).     

Homo‐ and Heteronuclear meso,meso‐(E)‐Ethene‐1,2‐diyl‐Linked Diporphyrins: Preparation,X‐ray Crystal Structure,Electronic Absorption and Emission Spectra and Density Functional Theory Calculations

Homo‐ and heteronuclear meso,meso‐(E)‐ethene‐1,2‐diyl‐linked diporphyrins have been prepared by the Suzuki coupling of porphyrinylboronates and iodovinylporphyrins. Combinations comprising 5,10,15‐triphenylporphyrin (TriPP) on both ends of the ethene‐1,2‐diyl bridge M₂10 (M₂=H₂/Ni, Ni₂, Ni/Zn, H₄, H₂Zn, Zn₂) and 5,15‐bis(3,5‐di‐tert‐butylphenyl)porphyrinato‐nickel(II) on one end and H₂, Ni, and ZnTriPP on the other ( M₂11 ), enable the first studies of this class of compounds possessing intrinsic polarity. The compounds were characterized by electronic absorption and steady state emission spectra, ¹H NMR spectra, and for the Ni₂ bis(TriPP) complex Ni₂10 , single crystal X‐ray structure determination. The crystal structure shows ruffled distortions of the porphyrin rings, typical of Ni^II porphyrins, and the (E)‐C₂H₂ bridge makes a dihedral angle of 50° with the mean planes of the macrocycles. The result is a stepped parallel arrangement of the porphyrin rings. The dihedral angles in the solid state reflect the interplay of steric and electronic effects of the bridge on interporphyrin communication. The emission spectra in particular, suggest energy transfer across the bridge is fast in conformations in which the bridge is nearly coplanar with the rings. Comparisons of the fluorescence behaviour of H₄10 and H₂Ni10 show strong quenching of the free base fluorescence when the complex is excited at the lower energy component of the Soret band, a feature associated in the literature with more planar conformations. TDDFT calculations on the gas‐phase optimized geometry of Ni₂10 reproduce the features of the experimental electronic absorption spectrum within 0.1 eV.     

Study of phase transitions in 4-n-alkoxybenzilidene-4′-n-alkylanilines by one and two dimensional 13C NMR

Abstract

The phase transition of a series of homologous liquid-crystalline compounds, nO.m (4-n-alkoxybenzilidene-4′-n-alkylanilines), from the nematic phase to the smectic A phase has been studied by ¹³C NMR. The order parameters, determined by a two dimensional technique called separated local field spectroscopy combined with off-magic angle spinning, of different molecular segments of these compounds are related linearly to the ¹³C chemical shifts. Changes in the order parameters of the phenyl rings as well as those of the chains during the S_A–N transition depend on the nature of the phase transition. These changes are quantitatively related to the McMillan ratio, which is defined as the ratio between the S_A–N transition temperature (T _SAN) and the nematic to isotropic transition temperature (T _NI), i.e. M = T _SAN/T _NI. The S_A–N transition is first order for M > M _TCP, and second order for M < M _TCP, where TCP is the tricritical point. The value of M _TCP was found to be 0·958 ± 0·004, in excellent agreement with that obtained from spin probe studies (0·959 ± 0·005) reported by Freed and co-workers [1].     

Die Lichtabsorption des Ni2+ und Co2+ in Molybdaten(VI)

Zusammenfassung Die Lichtabsorption von CoMoO₄, Co_0,1Mg_0,9MoO₄, NiMoO₄ und Ni_0,1Mg_0,9MoO₄ wird untersucht. Es zeigt sich, daß die verschiedenartigen Strukturen bei MolybdatenM ^IIMoO₄ (M ^II=Mg, Mn, Ni, Co) durch Unterschiede in der Kristallfeld-stabilisierung derM ^II bedingt sind.

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The absorption of light by CoMoO₄, Co_0,1Mg_0,9MoO₄, NiMoO₄ and Ni_0,1Mg_0,9MoO₄ has been investigated. It was found that the different types of structure of the molybdatesM ^IIMoO₄ (M ^II=Mg, Mn, Ni, Co) are due to differences of the crystal field stabilization ofM ^II.

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Mit 2 Abbildungen     

Developing Intense Blue and Magenta Colors in α‐LiZnBO3: The Role of 3d‐Metal Substitution and Coordination

We describe the synthesis, crystal structures, and optical absorption spectra/colors of 3d‐transition‐metal‐substituted α‐LiZnBO₃ derivatives: α‐LiZn_1?xM^II_xBO₃ (M^II=Co^II (0<x<0.50), Ni^II (0<x≤0.05), Cu^II (0<x≤0.10)) and α‐Li_1+xZn_1?2xM^III_xBO₃ (M^III=Mn^III (0<x≤0.10), Fe^III (0<x≤0.25)). The crystal structure of the host α‐LiZnBO₃, which is both disordered and distorted with respect to Li and Zn occupancies and coordination geometries, is largely retained in the derivatives, which gives rise to unique colors (blue for Co^II, magenta for Ni^II, violet for Cu^II) that could be of significance for the development of new, inexpensive, and environmentally friendly pigment materials, particularly in the case of the blue pigments. Accordingly, this work identifies distorted tetrahedral MO₄ (M=Co, Ni, Cu) structural units, with a long M?O bond that results in trigonal bipyramidal geometry, as new chromophores for blue, magenta, and violet colors in a α‐LiZnBO₃ host. From the L*a*b* color coordinates, we found that Co‐substituted compounds have an intense blue color that is stronger than that of CoAl₂O₄ and YIn_0.90Mn_0.10O₃. The near‐infrared (NIR) reflectance spectral studies indicate that these compounds exhibit a moderate IR reflectivity that could be significant for applications as “cool pigments”.     

Dimethyl telluride as a ligand: synthesis and physicochemical studies on its complexes with transition metal bis(chlorosulphates) M(SO3Cl)2(M=Cr,Mn, Fe,Co, Ni,Cu)

Summary Dimethyl telluride, Me₂Te, reacts with first row transition metal bis(chlorosulphates), M(SO₃Cl)₂(M=Cr^II, Mn^II, Fe^II, Co^II, Ni^II, Cu^II) in MeCN resulting in the formation of compounds of the type [M(SO₃Cl)₂-(Me₂Te)₂]. These compounds are stable under N₂ but decompose on exposure to moist air. The covalent nature of bonding of the SO₃Cl^– group has been ascertained on the basis of a positive shift in ₁ (A) vibration, splitting of the doubly degenerate (E) modes and low molar conductivity values. The magnetic moments and electronic spectra suggest an octahedral geometry for these compounds (except for the Ni^II complex where a tetragonal distortion is observed) where each SO₃Cl^– group is bonded in a bidentate manner.     

Raman study of cation distribution in the scheelite-like double molybdates and tungstates

Compounds M⁺ M³⁺ (TO₄)₂ have been investigated (M⁺, M³⁺ are alkaline and rare earth metals, respectively; T=Mo, W). The way of cation distribution (statistical or orderec) is given by the ratio of their ionic radii. The boundary between the distributions has been determinea: r _ion (M⁺)/r _ion (M³⁺)=1.3–1.32. In molybdates the cations are partly ordered even when M⁺ and M³⁺ have close dimensions because they interact with each other. The compounds KLa(MoO₄)₂ and KN l(MoO₄)₂ fall within the transition range and have, therefore, a complex polymorphic composition. The phase transition from the high-to low-temperature form of KLa(MoO₄)₂ is identical to the corresponding transition in KEu(MoO₄)₂ known from X-ray studies.Institute of Inorganic Chemistry, Siberian Branch, Russian Academy of Sciences. Translated fromZhurnal Struktumoi Khimii, Vol. 34, No. 4, pp. 42–58, July–August, 1993.Translated by L. Smolina     

Analysis of Corrosion Products Formed on Cu-Ni Alloys Immersed in Sea Water

Abstract

A method was developed for separation and analysis of corrosion products formed on the surface of Cu-Ni alloys immersed in sea water polluted by sulphide ions. This method is based on the selective dissolution of oxidation compounds by suitable solvents dissolving the metal matrix only to a negligeable extent.

The following solvents were used: 1) methanol to dissolve Na⁺, Cu²⁺, Ni²⁺ chlorides and sulphates; 2) glycine to dissolve bivalent metal compounds - Cu²⁺, Ni²⁺ oxides, sulphides, oxysulphates, oxychlorides and oxycarbonates; 3) ammonia solution to dissolve Cu⁺ compounds (i.e. Cu₂O and CuCl); 4) potassium cyanide to dissolve CU⁺ sulphides.

Reasonable agreement between chemical and X-Ray analysis results was observed only for copper compounds, since nickel and iron compounds could not tie observed by X-Ray diffraction. The results of Auger and chemical analyses better agree with each other, yet no Fe compounds could be detected. This is to be attributed to the non-homogeneous corrosion layer which notably contains Fe compounds in the innermost region at a depth where Auger spectroscopy is unable to detect them, whereas their detection is possible by chemical analysis, since it is a bulk analysis.     

Metallkomplexe der Phosphinsäuren. XVII. Untersuchungen zur Oligomerisation von NiII- und CoII-Komplexen bifunktioneller Dithiophosphinsäuren HS(S)P(R)-R′-(R)P(S)SH [2]

Metal Complexes of Phosphinic Acids. XVII. Investigations on the Oligomerisation of Ni^II and Co^II Complexes of Bifunctional Dithiophosphinic Acids Alkali or ammonium salts of bifunctional dithiophosphinic acids react with Ni²⁺ or Co²⁺ to give complexes [S₂P(R)? (CH₂)_n? (R)PS₂M]_m or _x (R = 4-methoxyphenyl; M = Ni²⁺, Co²⁺; n = 4? 10) some of which are soluble in organic solvents and of low molecular weight (m), while others are insoluble (x). According to magnetic and spectroscopic measurements all of them contain planar NiS₄ or tetrahedral CoS₄ chromophors. While the insoluble compounds are regarded as coordination polymers, it is shown by osmometric measurements and by ³¹P{¹H} spectroscopy, that there exists the equilibrium monomers (ansa type) ? oligomers in solutions of the soluble complexes. The influence of n on the solubility and the equilibrium is discussed. The association can be explained by simple statistic considerations.     

Synthesis and Characterization of a Dinuclear Nitrogen‐Rich Ferrocenyl Ligand and Its Ionic Coordination Compounds and Their Catalytic Effects During Combustion

Alkylferrocene‐based burning‐rate catalysts (BRCs) exhibit distinct migration tendency and high volatility and thus result in inferior performance of composite solid propellants during their combustion processes. To deal with these drawbacks, a novel dinuclear nitrogen‐rich ferrocene derivative, 4‐amino‐3,5‐bis(4‐ferrocenyl‐1,2,3‐triazolyl‐1‐methyl)‐1,2,4‐triazole (BFcTAZ) and its twenty seven ionic coordination compounds, [M₂(BFcTAZ)₂(H₂O)₄]_mX_n·xH₂O (M = Cr³⁺, Mn²⁺, Fe³⁺, Co²⁺, Ni²⁺, Cu²⁺, Zn²⁺, Cd²⁺ and Pb²; X = polycyano anions), were synthesized and characterized by FT‐IR, UV/Vis, and elementary analysis. Crystal structure of BFcTAZ was further confirmed by single‐crystal X‐ray diffraction and a general molecular structure of the new complexes was proposed. Their high thermal stability was verified by TG technique. Cyclic voltammetry studies suggested that the new compounds are diverse redox systems. Their effects on the thermal degradation of some common oxidizers were measured by DSC technique. The results indicated that most of the new complexes exert great effects on the thermal decomposition of AP, RDX, and 1,1‐diamino‐2,2‐dinitroethylene (FOX‐7) and some of them are more active than catocene. The Cu²⁺ complexes are among the excellent ones. However, only six compounds have appreciable catalytic activity in the thermal degradation of HMX.     

Synthesis and Characterization of α‐Titanium Phosphate/Propylamine Intercalation Compounds Containing Transition‐Metal Ions

Polycrystalline intercalated TiM_xH_2−nx(PO₄)₂· yC₃H₇NH₂·wH₂O compounds with transition metal (TM) ions (Mⁿ⁺ = Co²⁺, Ni²⁺, Fe³⁺ or Cr³⁺) have been prepared by means of an indirect route and characterised using X-ray diffraction, scanning electron microscopy, chemical and thermal analysis, X-ray absorption and magnetic measurements. These novel pillared layered materials, which were obtained from the monoclinic (P2₁/c space group) α-Ti(HPO₄)₂·H₂O phase, lose its crystallinity after intercalation. However all the TM ions are octahedrally surrounded by 6 oxygen atoms, although the X-ray absorption spectra evidence a clear dependence on the temperature. Surprisingly, all the materials behave as paramagnetic down to 1.5 K, but they exhibit different colours, what means that they are optically active (Co²⁺: violet; Ni²⁺: pale green; Fe³⁺: yellow; Cr³⁺: dark green).     

On the electronic structure of the Ni4+2 ion and its relation to the metal-metal bonding in binuclear Ni(II) complexes

In an attempt to improve the understanding of the electronic structure of the Ni²⁺ thiocarboxylates, we have analized, as a zeroth-order approximation, the electronic structure of the Ni⁴⁺₂ dimer in vacuo. Two small-size Slater-type orbitals (STO) basis sets have been used in order to study basis effects, referring particularly to the details of the d-d interactions. All the electrons have been included and all the molecular integrals have been computed accurately. All the multiplets of the {Ar₂}σ²_gσ²_gπ⁴_gπ⁴_uδ^x_gδ^4?x_u (x = 0 to 4) configurations have been calculated at different values of the Ni²⁺Ni²⁺ distance, R, ranging from 3.20 to 5.20 a.u. in the smaller basis calculation and from 3.20 to 4.20 a.u. in the larger basis calculation. Inclusion of configuration interaction (CI) limited to the δ^x_gσ^4?x_u (x = 0 to 4) configurations yields a ³Σ^?_g as the lowest multiplet. This CI reduces R_e from 2.03 to 1.76 Å, an effect also encountered in much more extensive CI calculations on Ni₂. The bonding in Ni⁴⁺₂ is discussed in terms of the R dependence of the orbital energies; σ, π, and δ interactions seem to make important contributions to the bonding, in view of their orbital splittings and stabilizations with respect to the free-ion values. The present results are compared with previous nonempirical studies on the Ni₂ and Ni⁺₂, as well as with empirical relationships among different molecular constants. The relevance of the results on Ni⁴⁺₂ to the question of the metal-metal interaction in {Ni(RCOS)₂}₂ compounds is difficult to discuss with certainty, but, mainly from the theoretical geometry obtained, it is argued that the Ni²⁺Ni²⁺ interactions might have a very small contribution to the selling of the electronic structure of the thiocarboxylates.     

Crystal structure and magnetism of layered Ln2Ca2MnNiO8 (Ln=Pr,Nd, Sm,and Gd) compounds

We report the syntheses, crystal structure, and magnetic properties of a series of distorted K₂NiF₄-type oxides Ln₂Ca₂MnNiO₈ (Ln=Pr, Nd, Sm, and Gd) in which Ln/Ca and Mn/Ni atoms randomly occupy the K and Ni sites respectively. The Ln=La compound does not form. These compounds show systematic distortions from the ideal tetragonal K₂NiF₄ structure (space group I4/mmm) to an orthorhombic structure (space group Pccn) with buckled MO₂ (M=Mn/Ni) layers. The degree of distortion is increased as the size of Ln decreases. Based on the magnetic data and X-ray absorption near edge spectra, we assigned Mn^IV and Ni^II. The Curie–Weiss plots of the high temperature magnetic data suggest strong ferromagnetic interactions probably due to Mn^IV–O–Ni^II linkages, implying local ordering of Mn/Ni ions to form ferromangnetic clusters in the MO₂ layers. At low temperatures below 110–130 K, these compounds show antiferromagnetic behaviors because of Mn^IV–O–Mn^IV and/or Ni^II–O–Ni^II contacts between the ferromagnetic clusters. The Ln=Pr and Nd compounds show additional antiferromagnetic signals that we attribute to the interlayer interactions between the clusters mediated by the Pr³⁺ and Nd³⁺ ions in the interlayer spaces. The present compounds show many parallels with the previously reported Ln₂Sr₂MnNiO₈ compounds.     

Metal Complexes of Macrocyclic Ligands. XII. A Complexone-like Tetraazamacrocycle

The complexone-like tetraazamacrocycle 1 (LH₄) forms a series of metal complexes with Co²⁺, Ni²⁺, Cu²⁺ and Zn²⁺ (M²⁺) of the type MLH₂, ML^2? and M₂L, which have been isolated and characterized by VIS., IR. and NMR. spectroscopy. Based on these results tentative structures for the different species are proposed.     

Six-coordinate dinuclear hexaazamacrocyclic complexes of nickel(II), copper(II) and zinc(II) with tetraamide group ligands

Summary A series of 20–24 membered macrocyclic dinuclear transition metal complexes [M₂L¹X₄]-[M₂L⁴X₄] (M = Ni^II, Cu^II or Zn^II; X = Cl or NO₃) have been synthesized by template condensation of diethylenetriamine with dicarboxylic acids. The bonding and stereochemistry of the complexes have been characterized by i.r.,¹H-n.m.r., e.p.r. and electronic spectral studies, magnetic susceptibility and conductivity measurements. The Ni and Zn complexes exhibit octahedral geometry around the metal ion, whereas the Cu complexes possess a distorted octahedral geometry. Each metal ion is coordinated by two amide nitrogens and two secondary nitrogens of the diethylenetriamine moiety; the fifth and sixth coordination sites are occupied by the anions.     

Flexible Molecular Precursors for Selective Decomposition to Nickel Sulfide or Nickel Phosphide for Water Splitting and Supercapacitance

Herein, the synthesis of three nickel(II) dithiophosphonate complexes of the type [Ni{S₂P(OR)(4-C₆H₄OMe)}₂] [R=H ( 1 ), C₃H₇ ( 2 )] and [Ni{S₂P(OR)(4-C₆H₄OEt}₂] [R=(C₆H₅)₂CH ( 3 )] is described; their structures were confirmed by single-crystal X-ray studies. These complexes were subjected to surfactant/solvent reactions at 300 °C for one hour as flexible molecular precursors to prepare either nickel sulfide or nickel phosphide particles. The decomposition of complex 2 in tri-octylphosphine oxide/1-octadecene (TOPO/ODE), TOPO/tri-n-octylphosphine (TOP), hexadecylamine (HDA)/TOP, and HDA/ODE yielded hexagonal NiS, Ni₂P, Ni₅P₄, and rhombohedral NiS, respectively. Similarly, the decomposition of complex 1 in TOPO/TOP and HDA/TOP yielded hexagonal Ni₂P and Ni₅P₄, respectively, and that of complex 3 in similar solvents led to hexagonal Ni₅P₄, with TOP as the likely phosphorus provider. Hexagonal NiS was prepared from the solvent-less decomposition of complexes 1 and 2 at 400 °C. NiS (rhom) had the best specific supercapacitance of 2304 F g⁻¹ at a scan rate of 2 mV s⁻¹ followed by 1672 F g⁻¹ of Ni₂P (hex). Similarly, NiS (rhom) and Ni₂P (hex) showed the highest power and energy densities of 7.4 kW kg⁻¹ and 54.16 W kg⁻¹ as well as 6.3 kW kg⁻¹ and 44.7 W kg⁻¹, respectively. Ni₅P₄ (hex) had the lowest recorded overpotential of 350 mV at a current density of 50 mA cm⁻² among the samples tested for the oxygen evolution reaction (OER). NiS (hex) and Ni₅P₄ (hex) had the lowest overpotentials of 231 and 235 mV to achieve a current density of 50 mA cm⁻², respectively, in hydrogen evolution reaction (HER) examinations.     

Magnetochemical Complexity of Hexa‐ and Heptanuclear Wheel Complexes of Late‐3d Ions Supported by N,O‐Donor Pyridyl–Methanolate Ligands

The scaffold geometries, stability and magnetic features of the (pyridine‐2‐yl)methanolate (L) supported wheel‐shaped transition‐metal complexes with compositions [M₆L₁₂] ( 1 ), [Na?(ML₂)₆]⁺ ( 2 ), and [M′?(ML₂)₆]²⁺ ( 3 ), in which M=Co^II, Ni^II, Cu^II, and Zn^II were investigated with density functional theory (DFT). The goals of this study are manifold: 1) To advance understanding of the magnetism in the synthesized compounds [Na?(ML₂)₆]⁺ and [M′?(ML₂)₆]²⁺ that were described in Angew. Chem. Int. Ed.­ 2010 , 49, 4443 ( I ‐{Na?Ni₆}, I ‐{Ni′?Ni₆}) and Dalton Trans.­ 2011 , 40, 10526 ( II ‐{Na?Co₆}, II ‐{Co′?Co₆}); 2) To disclose how the structural, electronic, and magnetic characteristics of 1 , 2 , and 3 change upon varying M^II from d⁷ (Co²⁺) to d¹⁰ (Zn²⁺); 3) To estimate the influence of the Na⁺ and M′²⁺ ions (X^Q+) occupying the central voids of 2 and 3 on the external and internal magnetic coupling interactions in these spin structures; 4) To assess the relative structural and electrochemical stabilities of 1 , 2 , and 3 . In particular, we focus here on the net spin polarization, the determination of the strength and the sign of the exchange coupling energies, the rationalization of the nature of the magnetic coupling, and the ground‐state structures of 1 , 2 , and 3 . Our study combines the broken symmetry DFT approach and the model Hamiltonian methodology implemented in the computational framework CONDON 2.0 for the modeling of molecular spin structures, to interpret magnetic susceptibility measurements of I ‐{Na?Ni₆} and I ‐{Ni′?Ni₆}. We illustrate that whereas the structures, stability and magnetism of 1 , 2 , and 3 are indeed influenced by the nature of 3d transition‐metals in the {M₆} rims, the X^Q+ ions in the inner cavities of 2 and 3 impact these properties to an even larger degree. As exemplified by I ‐{Ni′?Ni₆}, such heptanuclear complexes exhibit ground‐state multiplets that cannot be described by simplistic model of spin‐up and spin‐down metal centers. Furthermore, we assess how future low‐temperature susceptibility measurements at high magnetic fields can augment the investigation of compound 3 with M=Co, Ni.