Complexes of cobalt(II) aryl carboxylates with quinoline and isoquinoline

Summary Several new complexes of cobalt(II) aryl carboxylates Co(O₂CC₆H₄R)₂ (R =o-Me;o,m-Cl:o,m-NO₂ andm-MeO) have been prepared by refluxing an ethanolic solution of the respective cobalt(II) aryl carboxylate with quinoline (Q) and isoquinoline (IQ). The quinoline complexes are green or purple while isoquinoline complexes are pink to reddish pink. All are neutral and soluble in common organic solvents. Analytical data indicate that quinoline complexes are of 1:1 stoichiometry. Magnetic and spectral studies show them to possess the usual copper(II) acetate monohydrate type dimeric carboxylate bridged structures. formulated as Co₂(O₂CC₆H₄R)₄Q₂, in which cobalt(II) is in a square pyramidal geometry. By contrast, isoquinoline yields monomeric bisamine complexes oftrans-octahedral configuration containing bidentate chelating carboxylate groups.     

Antiferromagnetic coupling in [Mn<Subscript>12</Subscript>O<Subscript>12</Subscript>(O<Subscript>2</Subscript>CMe)<Subscript>6</Subscript>(<Emphasis Type="Italic">p</Emphasis>-CO<Subscript>2</Subscript>-phenyl nitronyl

The synthesis of [Mn₁₂O₁₂(O₂CMe)₆(p-CO₂-phenyl nitronyl nitroxide)₁₀(H₂O)₄]· 4H₂O, (1), by direct replacement of some of the acetate groups in [Mn₁₂O₁₂(O₂CMe)₁₆(H₂O)₄] · 4H₂O · 2MeCO₂H, (2), with the organic radical p-HO₂C-phenyl nitronyl nitroxide, (3), is reported. E.p.r. spectra show exchange narrowing in (1) due to coupling between the manganese ions and radicals. The isotropic hyperfine splitting constant from the manganese ions is a = 96 Oe at 5.5K. The magnetic susceptibility indicates antiferromagnetic exchange interactions between the manganese ions and the radicals with the Weiss constant = -25 K. The spin was determined to be S = 6 from magnetization data in the 2--30 K temperature range at 50 kOe, suggesting a mixture of ground state with excited states.     

Beiträge zum Koordinationsverhalten von Oxidionen in anorganischen Feststoffen. IV [1] Darstellung,Kristallstruktur und spektroskopische Charakterisierung von NiP4O11 und CaNiP2O7

Synthesis, Crystal Structures, and Spectroscopic Characterization of NiP₄O₁₁ and CaNiP₂O₇ From melts single crystals of NiP₄O₁₁ and CaNiP₂O₇ have been grown. These allowed refinement of the crystal structures (NiP₄O₁₁: C1¯, Z = 8, a = 12, 753(4)Å, b = 12.957(3)Å, c = 10.581(4)Å, α = 89.42(2)°, β = 116.96(2)°, γ = 90.20(2)°, R1 = 0.027, wR2 = 0.072 for 3058 I_o > 2σ (I_o), 3291 independent reflections, 290 parameters; CaNiP₂O₇: P1¯, Z = 2, a = 6.433(3)Å, b = 6.536(4)Å, c = 6.515(2)Å, α = 66.4(2)°, β = 87.5(2)°, γ = 82.7(2)°, R1 = 0.026, wR2 = 0.062 for 1624 I_o > 2σ (I_o), 2189 independent reflections, 101 parameter) and measurement of polarized electronic absorption spectra in the uv/vis/nir region (6000—32000 cm^—1). NiP₄O₁₁ is isotypic to the series of ultraphosphates MP₄O₁₁ (M = Mn, Fe, Co, Cu, Zn, Cd) that exhibit a two‐dimensional network formed from ten‐membered phosphate rings. CaNiP₂O₇ completes the series of diphosphates AMP₂O₇ (A: Ca, Sr, Ba; M = Cr — Zn) and is isotypic to CaCoP₂O₇. Ni²⁺ ions in both phosphates show distorted octahedral coordination. The electronic transitions associated with the chromophores [Ni²⁺O₆] are nicely reproduced by calculations within the framework of the angular overlap model (AOM). The parametrisation scheme leads to e_{σ, norm}(2.0Å) = 3690 cm^—1 and B = 896 cm^—1 (C/B = 4.2) for CaNiP₂O₇ and e_{σ, norm}(2.0Å) = 4150 cm^—1 and B = 948 cm^—1 (C/B = 4.5) for NiP₄O₁₁ (Δ_o(CaNiP₂O₇) = 6800 cm^—1; Δ_o(NiP₄O₁₁) = 7100 cm^—1).     

Direct Synthesis of Titanium Complexes with Chelating cis‐9,10‐Dihydrophenanthrenediamide Ligands through Sequential C?C Bond‐Forming Reactions from o‐Metalated Arylimines

A series of new titanium(IV) complexes with o‐metalated arylimine and/or cis‐9,10‐dihydrophenanthrenediamide ligands, [o‐C₆H₄(CH?NR)TiCl₃] (R=2,6‐iPr₂C₆H₃ ( 3 a ), 2,6‐Me₂C₆H₃ ( 3 b ), tBu ( 3 c )), [cis‐9,10‐PhenH₂(NR)₂TiCl₂] (PhenH₂=9,10‐dihydrophenanthrene; R=2,6‐iPr₂C₆H₃ ( 4 a ), 2,6‐Me₂C₆H₃ ( 4 b ), tBu ( 4 c )), [{cis‐9,10‐PhenH₂(NR)₂}{o‐C₆H₄(HC?NR)}TiCl] (R=2,6‐iPr₂C₆H₃ ( 5 a ), 2,6‐Me₂C₆H₃ ( 5 b ), tBu ( 5 c )), have been synthesised from the reactions of TiCl₄ with o‐C₆H₄(CH?NR)Li (R=2,6‐iPr₂C₆H₃, 2,6‐Me₂C₆H₃, tBu). Complexes 4 and 5 were formed unexpectedly from the reactions of TiCl₄ with two or three equivalents of the corresponding o‐C₆H₄(CH?NR)Li followed by sequential intramolecular C? C bond‐forming reductive elimination and oxidative coupling reactions. Attempts to isolate the intermediates, [{o‐C₆H₄(CH?NR)}₂TiCl₂] ( 2 ), were unsuccessful. All complexes were characterised by ¹H and ¹³C NMR spectroscopy, and the molecular structures of 3 a , 4 a – c , 5 a , and 5 c were determined by X‐ray crystallography.     

Metal complexes of hybrid oxygen — arsenic ligands. Part I. Complexes ofo-dialkyl/arylarsinobenzoic acids with chromium(III)

Summary Reactions of hybrid oxygen-arsenic ligands:o-R₂As-C₆H₄CO₂H (R = Me, Et, C₆H₁₁, Ph andp-tolyl) with CrO₃ and of their sodium salts withtrans-[CrCl₂(H₂O)₄]Cl·2H₂O in a 31 molar ratio yield three types of oxo/hydroxo bridged complexes:a. CrO(o-R₂AsC₆H₄CO₂)nH₂O (R=Me, n=1.5 or 2.5; R=Et, n=1 or 1.5; R=C₆H₁₁, n=1 or 3; R=p-tolyl, n=4),b. Cr(o-Ph₂AsC₆H₄CO₂)₂(OH)2.5 H₂O andc. Cr(o-R₂AsC₆H₄CO₂)(OH)₂nH₂O (R=Ph, n=1; R=p-tolyl, n=0.5). Their i.r. data favour symmetrical chelation of the carboxylate ion, with the metal ion leaving the arsenic(III) uncoordinated. Suitable dimeric, trimeric and tetrameric structures have been assigned for (i) Typea (R=C₆H₁₁, n=1), (ii) Typea (R=p-tolyl, n=4) and (iii) typea. (R= Et, n=1), Typeb. and Typec. (R=p-tolyl, n=0.5) complexes respectively on the basis of solution spectra and experimental molecular weights and _eff values. Calculated ligand field parameters (10 Dq and B) for all the complexes indicate covalent interaction between the metal ion and the ligands.     

Slow Relaxation of the Magnetization in Anilato-Based Dy(III) 2D Lattices

The search for two- and three-dimensional materials with slow relaxation of the magnetization (single-ion magnets, SIM and single-molecule magnets, SMM) has become a very active area in recent years. Here we show how it is possible to prepare two-dimensional SIMs by combining Dy(III) with two different anilato-type ligands (dianions of the 3,6-disubstituted-2,5-dihydroxy-1,4-benzoquinone: C₆O₄X₂²⁻, with X = H and Cl) in dimethyl sulfoxide (dmso). The two compounds prepared, formulated as: [Dy₂(C₆O₄H₂)₃(dmso)₂(H₂O)₂]·2dmso·18H₂O (1) and [Dy₂(C₆O₄Cl₂)₃(dmso)₄]·2dmso·2H₂O (2) show distorted hexagonal honeycomb layers with the solvent molecules (dmso and H₂O) located in the interlayer space and in the hexagonal channels that run perpendicular to the layers. The magnetic measurements of compounds 1, 2 and [Dy₂(C₆O₄(CN)Cl)₃(dmso)₆] (3), a recently reported related compound, show that the three compounds present slow relaxation of the magnetization. In compound 1 the SIM behaviour does not need the application of a DC field whereas 2 and 3 are field-induced SIM (FI-SIM) since they show slow relaxation of the magnetization when a DC field is applied. We discuss the differences observed in the crystal structures and magnetic properties based on the X group of the anilato ligands (H, Cl and Cl/CN) in 1–3 and in the recently reported derivative [Dy₂(C₆O₄Br₂)₃(dmso)₄]·2dmso·2H₂O (4) with X = Br, that is also a FI-SIM.     

Organomercury Compounds. 32. Syntheses of Fluorophenylmercurials by Decarboxylation

The organomercury compounds HgR₂ (R = 2-Cl,6-FC₆H₃, 2,6-F₂C₆H₃, 2,3,6-F₃C₆H₂, m-HC₆F₄, p-HC₆F₄, or C₆F₅) and RHg(O₂CR) (R = 2-Cl,6-C₆H₃, 2,6-F₂C₆H₃ or 2,3,6-F₃C₆H₂) have been obtained in moderate – good and low yields respectively from decarboxylation reactions of the corresponding mercury(II) fluorobenzoates in boiling pyridine. By contrast, mercury(II) 2,3,4-5-tetrafluorobenzoate gave a low yield of CO₂, a trace of Hg(o-HC₆F₄)₂ and a very low yield of o-HC₆F₄Hg(O₂CC₆F₄H-o). The ¹⁹⁹Hg NMR spectra of the diorganomercurials (R = 2-Cl,6-FC₆H₃, 2,6-F₂C₆H₃, 2,3,6-F₃C₆H₂, 2,4,6-F₃C₆H₂, 2,6-Cl₂C₆H₃, o-HC₆F₄, m-HC₆F₄, p-HC₆F₄ or C₆F₅) are discussed.     

Metal complexes of hybrid oxygen-arsenic ligands. Part V. A study of the products fromo-R2AsC6H4CO2M and CrO3 (M = H)/trans-[CrCl2(OH2)4]Cl · 2H2O (M = Na) in acetone

Summary A change of the reported medium of reaction oftrans- [CrCl₂(OH₂)₄]Cl · 2H₂O witho-R₂AsC₆H₄CO₂M (M = Na), from 95% ethanol to acetone, results in the change of an hydroxo — to an oxo — group (R = Ph), in the number of water molecules (R = Et or C₆H₁₁) and/or of ligand molecules (R =p-tolyl) in chromium(III)-arsine complexes. However, for R = Me, the same complex is obtained in each case. I.r. spectral data of these complexes favour the chelation of the carboxylate ion and non-coordination of arsenic(III) except for CrO(o-Ph₂AsC₆H₄CO₂) · 2.5 H₂O in which arsenic(III) of the monotertiary arsine group appears to coordinate to chromium(III). This would seem to be the first example of this type. On the other hand, the reaction of CrO₃ witho-R₂As- C₆H₄CO₂M (M = H) in 14.5 molar ratio in acetone yields only one type of complex,viz., [Cr₃O₃(o-R₂As(O)C₆H₄-CO₂)₂(o-R₂AsC₆H₄CO₂)(H₂O)₆] · n H₂O (n = 2, R = Me, C₆H₁₁ or Ph; n = O, R = Et). The arsine oxide molecules appear to chelate through As = 0 and the carboxylate oxygens while the arsine ligand binds only through the carboxylate oxygens leaving arsenic(III) uncoordinated as reported for the complexes obtained from the same reactants in 95% ethanol.     

Schiff base complexes of dioxouranium(VI). VII. Dioxouranium(VI) acetate complexes with monobasic bidentate and bibasic tridentateSchiff bases

11 and 12 molar reactions of dioxouranium(VI) acetate dihydrate with the monobasic bidentateSchiff bases,o-HOC₆H₄CH=NR oro-HOC₁₀H₆CH=NR (R=C₂H₅,n-C₃H₇,n-C₄H₉ or C₆H₅) and bibasic tridentateSchiff bases,o-HOC₆H₄CH=NR(OH) oro-HOC₁₀H₆CH=NR(OH) (R=–CH₂CH(CH₃)- or —CH₂CH₂CH₂–) have been studied and derivates of the type UO₂(OAc)₂(SBH), UO₂(OAc)₂(SBH)₂, UO₂(OAc)₂(SBH ₂) and UO₂(OAc)₂(SBH ₂)₂ (whereSBH andSBH ₂ represent monobasic bidentate and bibasic tridentateSchiff base molecules respectively) have been isolated. These have been characterized by elemental analysis, conductance measurements and IR spectral studies.

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UO₂ ²⁺-Komplexe von Schiff-Basen. VII. Uranylacetat-Komplexe mit monobasischen zweizähnigen und bibasischen dreizähnigen Schiff-Basen

Zusammenfassung Es wurden in 1:1- und 1:2-molaren Reaktionen von UO₂(OAc)₂·2H₂O mitSchiff-Basen (L) Komplexe des Typs UO₂(OAc)₂ L bzw. UO₂(OAc)₂ L ₂ isoliert. Die Komplexe wurden mittels Elementaranalyse, Leitfähigkeitsmessungen und IR-Spektren untersucht.

     

(Ni3–xMgx)[B3P3O12(OH)6] · 6 H2O (x ≈ 1.5): A Novel BorophosphateHydrate Containing Isolated Six‐Membered Rings of Tetrahedra

A novel borophosphate‐hydrate, (Ni_3–xMg_x)[B₃P₃O₁₂(OH)₆] · 6 H₂O (x ≈ 1.5), has been prepared by hydrothermal synthesis (T = 170 °C) from a mixture of NiCl₂ · 6 H₂O, Mg(OH)₂, B₂O₃ and H₃PO₄. The crystal structure was determined at 293 K from single‐crystal X‐ray diffraction data (trigonal, R3c (no. 167), a = 14.957(10) Å, c = 13.812(6) Å, V = 2676(2) ų, Z = 6, R₁ = 0.0276, wR₂ = 0.0714 for 779 observed reflections with I > 2σ(I)). The crystal structure contains unbranched six‐membered rings [B₃P₃O₁₂(OH)₆]^6– of alternating corner linked borate and phosphate tetrahedra, which are stacked along [001] and connected via M^IIO₂(OH)₂(H₂O)₂ coordination polyhedra. Hydrogen bonding between the tetrahedral six‐membered rings and M^IIO₂(OH)₂(H₂O)₂ octahedra leads to a further cross‐linking. With respect to the arrangement of isolated six‐membered tetrahedral rings the crystal structure of this borophosphate‐hydrate is closely related to the cyclo‐hexasilicate dioptase, Cu₆[Si₆O₁₈] · 6 H₂O.     

Two New Benzoate‐di(methylcyclopentadienyl)ytterbium(III) Complexes: [Yb(MeCp)2(O2CC6F5)]2 and [Yb(MeCp)2(O2C‐o‐HC6F4)]2

Transparent orange crystals of [Yb(MeCp)₂(O₂CC₆F₅)]₂ and [Yb(MeCp)₂(O₂C‐o‐HC₆F₄)]₂ were obtained by oxidation of Yb(MeCp)₂ with M(O₂CR) (M = ¹/₂ Hg, Tl; R = C₆F₅, o‐HC₆F₄) in tetrahydrofuran. They have a dimeric structure with bridging bidentate (O, O')‐benzoate groups and eight coordinated ytterbium. Both crystallise isotypic in the orthorhombic space group Pbca. Room temperature as well as low temperature single crystal X‐ray investigations show the o‐H/F positions in [Yb(MeCp)₂(O₂C‐o‐HC₆F₄)]₂ not to be ordered.     

Two ZnII‐based MOFs constructed with biphenyl‐2,2′,5,5′‐tetracarboxylic acid and flexible N‐donor ligands: syntheses,structures and properties

Two new Zn²⁺‐based metal–organic frameworks (MOFs) based on biphenyl‐2,2′,5,5′‐tetracarboxylic acid, i.e. H₄(o,m‐bpta), and N‐donor ligands, namely, poly[[(μ₄‐biphenyl‐2,2′,5,5′‐tetracarboxylato)bis{[1,3‐phenylenebis(methylene)]bis(1H‐imidazole)}dizinc(II)] dimethylformamide monosolvate dihydrate], {[Zn₂(C₁₆H₆O₈)(C₁₄H₁₄N₄)₂]·C₃H₇NO·2H₂O}_n or {[Zn₂(o,m‐bpta)(1,3‐bimb)₂]·C₃H₇NO·2H₂O}_n ( 1 ) {1,3‐bimb = [1,3‐phenylenebis(methylene)]bis(1H‐imidazole)}, and poly[[(μ₄‐biphenyl‐2,2′,5,5′‐tetracarboxylato)bis{[1,4‐phenylenebis(methylene)]bis(1H‐imidazole)}dizinc(II)] monohydrate], {[Zn₂(C₁₆H₆O₈)(C₁₄H₁₄N₄)₂]·H₂O}_n or {[Zn₂(o,m‐bpta)(1,4‐bimb)₂]·H₂O}_n ( 2 ) {1,4‐bimb = [1,4‐phenylenebis(methylene)]bis(1H‐imidazole)}, have been synthesized under solvothermal conditions. The complexes were characterized by IR spectroscopy, elemental analysis, single‐crystal X‐ray diffraction and powder X‐ray diffraction analysis. Structurally, the (o,m‐bpta)^4? ligands are fully deprotonated and combine with Zn²⁺ ions in μ₄‐coordination modes. Complex 1 is a (3,4)‐connected porous network with honeycomb‐like [Zn₂(o,m‐bpta)]_n sheets formed by 4‐connected (o,m‐bpta)^4? ligands. Complex 2 exhibits a (2,4)‐connected network formed by 4‐connected (o,m‐bpta)^4? ligands linking Zn²⁺ ions in left‐handed helical chains. The cis‐configured 1,3‐bimb and 1,4‐bimb ligands bridge Zn²⁺ ions to form multi‐membered [Zn₂(bimb)₂] loops. Optically, the complexes show strong fluorescence and display larger red shifts compared to free H₄(o,m‐bpta). Complex 2 shows ferroelectric properties due to crystallizing in the C_2v polar point group.     

Phosphine-Stabilized Pnictinidenes

The reaction of the intramolecular germylene-phosphine Lewis pair (o-PPh₂)C₆H₄GeAr* ( 1 ) with Group 15 element trichlorides ECl₃ (E=P, As, Sb) was investigated. After oxidative addition, the resulting compounds (o-PPh₂)C₆H₄(Ar*)Ge(Cl)ECl₂ ( 2 : E=P, 3 : E=As, 4 : E=Sb) were reduced by using sodium metal or LiHBEt₃. The molecular structures of the phosphine-stabilized phosphinidene (o-PPh₂)C₆H₄(Ar*)Ge(Cl)P ( 5 ), arsinidene (o-PPh₂)C₆H₄(Ar*)Ge(Cl)As ( 6 ) and stibinidene (o-PPh₂)C₆H₄(Ar*)Ge(Cl)Sb ( 7 ) are presented; they feature a two-coordinate low-valent Group 15 element. After chloride abstraction, a cyclic germaphosphene [(o-PPh₂)C₆H₄(Ar*)GeP] [B(C₆H₃(CF₃)₂)₄] ( 8 ) was isolated. The ³¹P NMR data of the germaphosphene were compared with literature examples and analyzed by quantum chemical calculations. The phosphinidene was treated with [iBu₂AlH]₂, and the product of an Al−H addition to the low-valent phosphorus atom (o-PPh₂)C₆H₄(Ar*)Ge(H)P(H)Al(C₄H₉)₂ ( 9 ) was characterized.     

ortho-, meta- and para-nitrophenylgold(I) complexes

Treatment of [BzPh₃P][AuCl₂] with [Hg(x-C₆H₄NO₂)₂] (x = o, m, or p) gives anionic gold(I) complexes of the type [BzPh₃P][Au(R)Cl](R = o-, m- or p-C₆H₄NO₂, Bz = C₆H₅CH₂). The chloro ligand in [Au(o-C₆H₄NO₂)Cl]^? can be replaced by bromo or iodo ligands by use of NaBr or NaI. The anions [Au(R)Cl]^? react with neutral monodentate ligands, L, to give neutral mononuclear complexes [Au(R)L] (R = o-C₆H₄NO₂, L = PPh₃, AsPh₃; R = m-C₆H₄NO₂, L = PPh₃) and with 1,2-bis(diphenylphosphino)ethane (dpe) to give [Au₂(R)₂(dpe)] (R = o-C₆H₄NO₂). The corresponding [Au(p-C₆H₄NO₂)Cl]^? reacts with PPh₃ or AsPh₃ to give mixtures containing [AuClL]. The anionic ortho-nitrophenylgold(I) complex is much more stable than its meta- or para-nitrophenyl isomers. These are thought to be the first reports of nitrophenylgold(I) complexes.     

Homo- and hetero-bimetallic glycolates and triethanolaminates of niobium

[Nb(OⁱPr)₅] reacts with 2,5-dimethylhexane-2,5-diol (LH₂), 2,3-dimethylbutane-2,3-diol (L¹H₂) and triethanolamine (teaH₃) in different stoichiometric ratios to yield complexes of the types: [Nb(OⁱPr)₃(L)] (1), [Nb(OⁱPr)(L)₂] (2), [Nb(L)₂(LH)] (3), [Nb(L¹)₂(L¹H)] (4) and [Nb(tea)(teaH)] (5). Equimolar reactions of (3), (4) and (5) with Al(OⁱPr)₃, Ti(OⁱPr)₄ and [Ta(OⁱPr)₅] yield novel heterobimetallic isopropoxide-glycolate (6)–(9) and -triethanolaminate (10)–(12) derivatives. Reactions in appropriate molar ratios of (1), (2) and (10) with alkoxyethanols [ROC₂H₄OH; R = Me, Et] and acetylacetone [acacH] give derivatives [(MeOC₂H₄O)₃Nb(L)] (13), [(acac)Nb(L)₂] (14), [Nb(tea)₂{Al(OC₂H₄OMe)₂}] (15), [Nb(tea)₂{Al(OC₂H₄OEt)₂}] (16) and [Nb(tea)₂{Al(acac)₂}] (17). The complexes (6), (8) and (10) on reaction with an excess of t-BuOH give the tert-butoxo analogues (18), (19) and (20), respectively. These new derivatives have been characterized by elemental analyses, spectroscopic studies and molecular weight measurements.     

Syntheses,crystal structures and electrochemistry of divalent metal 4-methylbenzenesulfonate complexes with o-phenanthroline

Three new compounds, namely [Mn(phen)₂(L)₂] · EtOH (1), [Zn(phen)₂(H₂O)₂]2L · 6H₂O (2) and [Cd(phen)₂(H₂O)₂]2L · 6H₂O (3), where HL = 4-methylbenzenesulfonic acid and phen = o-phenanthroline, have been synthesized, and their crystal structures determined by X-ray diffraction. In the complexes the metal atoms have two different coordination environments. Complex (1) consists of neutral molecules, [Mn(phen)₂(L)₂], in which Mn^II is six-coordinated by four nitrogen atoms from two o-phenanthroline molecules and two oxygen atoms from two sulfonate ions. Complexes (2) and (3) are isomorphous, each consisting of cationic species [M(phen)₂(H₂O)₂]²⁺ [M = Zn (2), Cd (3)], in which M^II is six-coordinated by four nitrogen atoms from two o-phenanthroline molecules and two water molecules. The electrochemical behavior and FT-IR of these compounds were also studied in detail.     

Examining the thermolysis reactions of nanoscopic Mn12 single molecule magnets

The thermal behavior of three Mn₁₂ single molecule magnets [Mn₁₂O₁₂(O₂CC₆H₅)₁₆(H₂O)₄]·CH₂Cl₂·C₆H₅CO₂H (1), [Mn₁₂O₁₂(O₂C^tBu)₁₆(H₂O)₄] (2) and [Mn₁₂O₁₂(O₂CCHCl₂)₁₆(H₂O)₄] (3) is reported. Aromatic ligands allow the complex 1 to be stable up to 300 °C whereas alkyl groups decrease drastically the domain of thermal stability for the complexes 2 and 3. Moreover, the thermal decarboxylation of complexes 2 and 3 generates [Mn₆O₂(O₂CR)₁₀L₄] (L=H₂O, HO₂CR) complexes as characterized by single crystal X-ray diffraction when R=^tBu.     

Synthesis,Crystal Structure and Vibrational Spectra of Barium Cyclotetraphosphate Hydrate Ba2(P4O12)&#8729;3.5H2O

Barium tetrametaphosphate hydrate Ba₂(P₄O₁₂)&#8729;3.5H₂O was synthesized as a single‐phase crystalline powder starting from an aqueous solution of barium hydroxide and phosphorus pentoxide at 300 K. Ba₂(P₄O₁₂)&#8729;3.5H₂O crystallizes in a new structure type in which the Ba²⁺ ions form a distorted hexagonal diamond‐like arrangement with the (P₄O₁₂)^4– anions in the trigonal prismatic voids (Ba₂(P₄O₁₂)&#8729;3.5H₂O, C2/c, Z = 4, a = 777.3(2), b = 1297.6(2), c = 1346.1(3) pm, b = 95.38(2)°, wR₂ = 0.071, R₁ = 0.018, 1180 reflections, 118 parameters). The vibrational spectra of Ba₂(P₄O₁₂)&#8729;3.5H₂O and its thermal behavior up to 720 K are also reported.     

Crystal Structures of [Mn2(H2O)4(bpy)2(C8H12O4)2] · 2 H2O and [Mn(H2O)2(bpy)(C8H12O4)2/2] · H2O with bpy = 2,2′‐bipyridine

Reaction of MnSO₄ · H₂O, 2,2′‐bipyridine (bpy), suberic acid and Na₂CO₃ in CH₃OH/H₂O yielded a mixture of [Mn₂(H₂O)₄(bpy)₂(C₈H₁₂O₄)₂] · 2 H₂O ( 1 ) and [Mn(H₂O)₂‐ (bpy)(C₈H₁₂O₄)_2/2] · H₂O ( 2 ). In both complexes, the Mn atoms are octahedrally coordinated by two N atoms of one bpy ligand and four O atoms of two trans positioned H₂O molecules and two suberato ligands (d(Mn–O) = 2.107–2.328 Å; d(Mn–N) = 2.250–2.330 Å). The bis‐monodentate suberato ligands bridge Mn atoms to form dinuclear [Mn₂(H₂O)₄(bpy)₂(C₈H₁₂O₄)₂] complex molecules in 1 and 1D [Mn(H₂O)₂(bpy)(C₈H₁₂O₄)_2/2] chains in 2 . Via the intermolecular hydrogen bondings and π‐π stacking interactions, the dinuclear molecules in 1 are assembled into 2D networks parallel to (100), between which the crystal H₂O molecules are sandwiched. The polymeric chains in 2 are linked together by interchain hydrogen bonding and π‐π stacking interactions into 3D networks with the crystal H₂O molecules located in tunnels along [010]. Crystal data for 1 : P2₁/c (no. 14), a = 10.092(1) Å, b = 11.916(2) Å, c = 17.296(2) Å, β = 93.41(1)° and Z = 2. Crystal data for 2 : P2₁/c (no. 14), a = 11.176(2) Å, b = 9.688(1) Å, c = 37.842(6) Å, β = 90.06(1)° and Z = 8.     

(Carbonyl)Iron‐Selenolates: New Synthetic Methods and Reactions with Electrophiles. Crystal Structures of [(CO)6Fe2(μ‐SeR)2]; R = Me3SiCH2 and p‐O2NC6H4CH2, {(CO)6Fe2[μ‐η2‐Se,Se′‐o‐(SeCH2C6H4CH2Se)]}, and [(CO)6Fe2(μ‐SeFe(CO)2cp)2]

The reactions of Fe(CO)₅ or Fe₃(CO)₁₂ with NaBEt₃H or KB[CH(CH₃)C₂H₅]₃H, respectively and treatment of the resulting carbonylates M₂Fe(CO)₄, M = Na, K with elemental selenium in appropriate ratios lead to the formation of M₂[Fe₂(CO)₆(μ‐Se)₂]. Subsequent reactions with organo halides or the complex fragment cpFe(CO)₂⁺, cp = η⁵‐C₅H₅ afforded the selenolato complexes [Fe₂(CO)₆(μ‐SeR)₂], R = CH₂SiMe₃ ( 1 ), CH₂Ph ( 2 ), p‐CH₂C₆H₄NO₂ ( 3 ), o‐CH₂C₆H₄CH₂ ( 4 ) and cpFe(CO)₂⁺ ( 5 ) in moderate to good yields. A similar reaction employing Ru₃(CO)₁₂, Se and p‐O₂NC₆H₄CH₂Br leads to the formation of the corresponding organic diselenide. The X‐ray structures of 1 , 3 , 4 and 5 were determined and revealed butterfly structures of the Fe₂Se₂ cores. The substituents in 1 , 3  and 5 adopt different conformations depending on their steric demand. In 4 , the conformation is fixed because of the chelate effect of the ligand. The Fe–Se bond lengths lie in the range 235 to 240 pm, with corresponding Fe–Fe bond lengths of 254 to 256 pm. The ⁷⁷Se NMR data of the new complexes are discussed and compared with the corresponding data of related complexes.