Synthese von Kupfer- und Silberkomplexen mit fünfzähnigen N,S- und sechszähnigen N,O-Chelatliganden – Charakterisierung und Kristallstrukturen von {Cu2[C6H4(SO2)NC(O)]2(C5H5N)4}, {Cu2[C5H3N(CHNC6H4SCH3)2]2}(PF6)2 und {Ag[C5H3N(CHNC6H4SCH3)2]}PO2F2

Synthesis of Copper and Silver Complexes with Pentadentate N,S and Hexadentate N,O Chelate Ligands – Characterization and Crystal Structures of {Cu₂[C₆H₄(SO₂)NC(O)]₂(C₅H₅N)₄}, {Cu₂[C₅H₃N(CHNC₆H₄SCH₃)₂]₂}(PF₆)₂, and {Ag[C₅H₃N(CHNC₆H₄SCH₃)₂]}PO₂F₂ In the course of the reaction of copper(II)-acetate monohydrate with 2,2′-bisbenzo[d][1,3]thiazolidyl in methanol the organic component is transformed to N,N′-bis-(2-thiophenyl)ethanediimine and subsequently oxidized to the N,N′-bis-(2-benzenesulfonyl)ethanediaciddiamide H₄BBSED, which coordinates in its deprotonated form two Cu²⁺ ions. Crystallisation from pyridine/n-hexane yields [Cu₂(BBSED)(py)₄] · MeOH. It forms triclinic crystals with the space group P1 and a = 995.5(2) pm, b = 1076.1(3) pm, c = 1120.7(2) pm, α = 104.17(1)°, β = 105.28(1)°, γ = 113.10(1)° and Z = 1. In the centrosymmetrical dinuclear complex the copper ions are coordinated in a square-pyramidal arrangement by three nitrogen and two oxygen atoms. The Jahn-Teller effect causes an elongation of the axial bond by approximately 30 pm. The reactions of the pentadentate ligand 2,6-Bis-[(2- methylthiophenyl)-2-azaethenyl]pyridine BMTEP with salts of copper(I), copper(II) and silver(I) yield the complexes [CU₂(BMTEP)₂](PF₆)₂, [Cu(BMTEP)]X₂ (X = BF, C1O) and [Ag(BMTEP)]X (X = PO₂F, ClO). [Cu₂(BMTEP)₂](PF₆)₂ crystallizes from acetone/diisopropyl- ether in form of monoclinic crystals with the space group C2/c, and a = 1833.2(3) pm, b = 2267.30(14) pm, c = 1323.5(2) pm, β= 118.286(5)°, and 2 = 4. In the dinuclear complex cation with the symmetry C₂ the copper ions are tetrahedrally coordinated by two bridging BMTEP ligands. The Cu? Cu distance of 278.3pm can be interpreted with weak Cu? Cu interactions which also manifest itself in a temperature independent paramagnetism of 0.45 B.M. The monomeric silver complex [Ag(BMTEP)]PO₂F₂ crystallizes from acetone/thf in the triclinic space group P1 with a = 768.7(3) pm, b = 1074.0(5) pm, c = 1356.8(5) pm, α = 99.52(2)°, β = 96.83(2)°, γ = 99.83(2)° and Z = 2. The central silver ion is coordinated by one sulfur and three nitrogen atoms of the ligand in a planar, semicircular arrangement. The bond lengths Ag? N = 240.4–261.7 and Ag? S = 257.2 pm are significantly elongated in comparison with single bonds.     

Metallorganische Verbindungen der Lanthanoide. 111. Synthese und Charakterisierung kationischer Metallocen-Komplexe der Lanthanoide. Röntgenstrukturanalyse von [CpYb(THF)2][BPh4]

Organometallic Compounds of the Lanthanoids. 111. Synthesis and Characterization of Cationic Metallocene Complexes of the Lanthanoides. X-Ray Crystal Structure of [Cp Yb(THF)₂][BPh₄] Cationic organolanthanoide compounds [(C₅H₄R)₂Sm(THF)₂][BPh₄] (R = ^tBu ( 1 ), SiMe₃ ( 2 )), [PyrSm(THF)][BPh₄] ( 3 ) (Pyr* = NC₄H₂^tBu₂-2,5), [CpLn(THF)₂][BPh₄] (Cp* = C₅Me₅; Ln = Y ( 4 ), Yb ( 5 )), and [(C₅Me₄Et)₂ Ln(THF)₂][BPh₄] (Ln = Y ( 6 ), Sm ( 7 )) have been synthesized by oxidation of the divalent metallocenes [(C₅H₄R)₂Sm(THF)₂] (R = ^tBu, SiMe₃), [PyrSm(THF)], [CpYb(THF), and [(C₅Me₄Et)₂Sm(THF)] with Ag[BPh₄] and by protolysis of the lanthanoide alkyls [CpYMe(THF)], [CpYbCH(SiMe₃)₂], and [(C₅Me₄Et)₂LnCH(SiMe₃)₂] (Ln = Y, Sm) by [NEt₃H][BPh₄]. The ¹H- and ¹³C-NMR spectra of the new compounds are discussed. 5 crystallizes in the space group P2₁/c with a = 10.604(7), b = 21.749(3), c = 19.124(4) Å, β = 96.47(4)°, Z = 4 and V = 4383(3) ų (R = 0.0291 for 8517 observed reflections with F_o ≥ 4σ (F_o).     

Physicochemical characterization of the dimeric lanthanide complexes [en{Ln(DO3A)(H2O)}2] and [pi{Ln(DTTA)(H2O)}2]2-: a variable-temperature 17O NMR study

The Gd(III) complexes of the two dimeric ligands [en(DO3A)2] {N,N'-bis[1,4,7-tris(carboxymethyl)-1,4,7,10-tetraazacyclododecan-10-yl-methylcarbonyl]-N,N'-ethylenediamine} and [pi(DTTA)2]8- [bisdiethylenetriaminepentaacetic acid (trans-1,2-cyclohexanediamine)] were synthesized and characterized. The 17O NMR chemical shift of H2O induced by [en{Dy(DO3A)}2] and [pi{Dy(DTTA)}2]2- at pH 6.80 proved the presence of 2.1 and 2.2 inner-sphere water molecules, respectively. Water proton spin-lattice relaxation rates for [en{Gd(DO3A)(H2O)}2] and [pi{Gd(DTTA)(H2O)}2]2- at 37.0 +/- 0.1 degrees C and 20 MHz are 3.60 +/- 0.05 and 5.25 +/- 0.05 mM(-1) s(-1) per Gd, respectively. The EPR transverse electronic relaxation rate and 17O NMR transverse relaxation time for the exchange lifetime of the coordinated H2O molecule and the 2H NMR longitudinal relaxation rate of the deuterated diamagnetic lanthanum complex for the rotational correlation time were thoroughly investigated, and the results were compared with those reported previously for other lanthanide(III) complexes. The exchange lifetimes for [en{Gd(DO3A)(H2O)}2] (769 +/- 10 ns) and [pi{Gd(DTTA)(H2O)}2]2- (910 +/- 10 ns) are significantly higher than those of [Gd(DOTA)(H2O)]- (243 ns) and [Gd(DTPA)(H2O)]2- (303 ns) complexes. The rotational correlation times for [en{Gd(DO3A)(H2O)}2] (150 +/- 11 ps) and [pi{Gd(DTTA)(H2O)}2]2- (130 +/- 12 ps) are slightly greater than those of [Gd(DOTA)(H2O)]- (77 ps) and [Gd(DTPA)(H2O)]2- (58 ps) complexes. The marked increase in relaxivity (r1) of [en{Gd(DO3A)(H2O)}2] and [pi{Gd(DTTA)(H2O)}2]2- result mainly from their longer rotational correlation time and higher molecular weight.     

Reaktion von cyclopentadienyl-substituierten Molybdän(V)-tetrachloriden mit LiPH(2,4,6-BuC6H2) und KPPh2(Dioxan)2. Molekülstrukturen von [Cp0Mo(μ-Cl)2]2 und [CpMo2(μ-Cl)3(μ-PPh2)] (Cp0 = C5Me4Et)

Reaction of Cyclopentadienyl Substituted Molybdenum(V) Tetrachlorides with LiPH(2,4,6-Bu C₆H₂) and KPPh₂(Dioxane)₂. Crystal Structures of [Cp⁰Mo(μ? Cl)₂]₂ and [Cp Mo₂(μ? Cl)₃(μ? PPh₂)] (Cp⁰ = C₅Me₄Et) The reaction of [Cp⁰Mo(CO)₃]₂ (Cp⁰ = C₅Me₄Et) and [Cp′Mo(CO)₃]₂ (Cp′ = C₅H₄Me) with PCl₅ in CH₃CN furnishes the Mo(V) complexes Cp⁰MoCl₄(CH₃CN) 1 and Cp′MoCl₄(CH₃CN) 2 in good yields. While 1 and 2 are reduced by LiPH(2,4,6-BuC₆H₂) to the Mo(III) complexes [Cp⁰Mo(μ? Cl)₂]₂ 3 and [Cp′Mo(μ? Cl)₂]₂ 4 , the reaction of 1 with KPPh₂(dioxane)₂ yields the reduction/substitution product [CpMo₂(μ? Cl)₃(μ? PPh)] 5 in low yield. 1 – 4 were characterized spectroscopically (i.r., mass, 3 and 4 also n.m.r.). An X-ray crystal structure determination was carried out on 3 and 5. 3 crystallizes in the triclinic space group P1 (No. 2) with a = 8.278(4), b = 12.508(7), c = 12.826(7) Å, α = 86.78(5), β = 81.55(2), γ = 75.65(4)°, V = 1 272.4 ų and two formula units in the unit cell (data collection at ? 67°C, 4 255 independent observed reflections, R = 2.9%); 5 crystallizes in the triclinic space group P1 (No. 2) with a = 11.536(8), b = 12.307(9), c = 13.157(9) Å, α = 91.41(6), β = 100.42(5), γ = 112.26(6)°, V = 1 688.7 ų and two formula units in the unit cell (data collection at ? 60°C, 6 147 independent observed reflections, R = 4.9%). The crystal structure of 3 shows the presence of centrosymmetric dimeric molecules with four bridging chloro ligands. In 5, two Mo atoms are bridged by three chloro ligands and one PPh₂ ligand. The Mo? Mo bond length in 3 and 5 (2.600(2), 2.596(2) Å and 2.6388(8) Å) is in agreement with a Mo? Mo bond.     

Synthesis and Crystal Structure of Lanthanide Schiff Base Complex [2-OC6H4CHN（2,6-i-Pr2C6H3）]2ErCl（THF）

1 INTRODUCTION The Schiff base ligands have been used to provide a stereochemically rigid ligand framework in homogenous precatalysts of some metals, such as salen Cr catalysts in asymmetric ring-opening re- action of epoxide[1] and salen Al in ring-opening polymerization of lactide and related cyclic esters[2]. Recently, it was reported that the bidentate Schiff base complexes of early and late transition metals can be served as promising alternatives to metal- locene catalysts for th…     

Diorganotin(IV) complexes of dideprotonated pyridoxine (PN, vitamin B6). The crystal structures of [SnEt2(PN-2H)] · CH3OH, [SnEt2(PN-2H)(DMSO)] and [SnBu2(PN-2H)]

The reactions of dimethyl-, diethyl- and dibutyltin(IV) oxides with pyridoxine (PN) in toluene/ethanol led to the formation of compounds [SnR₂(PN-2H)] which were characterized by EI and FAB mass spectrometry and by IR, Raman, Mössbauer and ¹H, ¹³C and ¹¹⁹Sn NMR spectroscopy. The structures of [SnEt₂(PN-2H)] · CH₃OH, [SnBu₂(PN-2H)] and [SnEt₂(PN-2H)(DMSO)] were determined by X-ray diffractometry. The first two contain dimeric [SnR₂(PN-2H)]₂ units in which two bridging-chelating pyridoxinate anions link the Sn atoms, while in [SnEt₂(PN-2H)(DMSO)] the DMSO coordinates to the tin atom via its O atom in a similar dimeric unit.     

Synthese und Kristallstrukturen der Samarium-Komplexe [SmI2(DME)3] und [Sm2I(NPPh3)5(DME)]

Synthesis and Crystal Structures of the Samarium Complexes [SmI₂(DME)₃] and [Sm₂I(NPPh₃)₅(DME)] When treated with ultrasound, the reaction of samarium metal with N-iodine-triphenylphosphaneimine in 1,2-dimethoxyethane (DME) leads to the two samarium complexes [SmI₂(DME)₃] ( 1 ) and [Sm₂I(NPPh₃)₅(DME)] ( 2 ), which are separated from each other by fractional crystallization. 1 could be isolated in two different crystallographic forms, namely as brownish black crystals ( 1 a ) and as violet-black crystals ( 1 b ), both of them are characterized by crystal structure analyses. 1 a : Space group P2₁/c, Z = 4, lattice dimensions at –80 °C: a = 1459.4(1), b = 1314.4(1), c = 2293.6(2) pm, β = 99.245(8)°, R = 0.0344. The structure of 1 a holds two crystallographically independent molecules [SmI₂(DME)₃], in which the samarium atoms have coordination number eight. The two individuals differ from each other particularly in their I–Sm–I bond angles, which are 157.94 and 178.45°. 1 b : Space group P2₁, Z = 2, lattice dimensions at –80 °C: a = 849.4(3), b = 1060.1(3), c = 1235.1(6) pm, b = 93.86(5)°, R = 0.0251. 1 b has a molecular structure similar to that of 1a with a bond angle I–Sm–I of 158.40°. The phosphoraneiminato complex [Sm₂I(NPPh₃)₅(DME)] ( 2 ) forms colourless, moisture sensitive crystals which contain two molecules DME per formula unit. 2 · 2 DME: Space group P1, Z = 2, lattice dimensions at –80 °C: a = 1405.0(4), b = 1656.5(3), c = 2208.3(7) pm, α = 89.60(3)°, β = 72.96(4)°, γ = 78.70(3)°, R = 0.0408. In 2 the two samarium atoms are linked via the μ-N atoms of two phosphoraneiminato ligands to form a planar Sm₂N₂ four-membered ring. One of the Sm atoms is terminally coordinated by the N atoms of two (NPPh₃)^– groups, thus achieving a distorted tetrahedral surrounding. The second Sm atom is coordinated by the N atom of one (NPPh₃)^– group, by the terminally bonded iodine atom, and by the O atoms of the DME chelate, thus achieving a distorted octahedral surrounding.     

Darstellung und Kristallstruktur der Kupfer(I)-chalkogenolat-2,2′-Bipyridin-Komplexe [CuS(2,4,6-iPr3C6H2)]4(Bipy)2 und [CuSe(2,4,6-iPr3C6H2)]2(Bipy)2

Synthesis and Structure of Copper(I)Chalcogenolate-2,2′-Bipyridine Complexes [CuS(2,4,6-iPr₃C₆H₂)]₄(Bipy)₂ and [CuSe(2,4,6-iPr₃C₆H₂)]₂(Bipy)₂ The oligomeric homoleptical copper(I) chalcogenolate compounds [CuS(2,4,6-iPr₃C₆H₂)]_x=4,8 and [CuSe(2,4,6-iPr₃C₆H₂)]₆ react with 2,2′-bipyridine (Bipy) to yield the tetranuclear complex [CuS(2,4,6-iPr₃C₆H₂)]₄(Bipy)₂ ( 4 ) and the dinuclear complex [CuSe(2,4,6-iPr₃C₆H₂)]₂(Bipy)₂ ( 5 ). The structures of 4 and 5 were determined by X-ray analysis. In the eight-membered Cu₄S₄ core of 4 with chair conformation the copper atoms are linked by μ₂-bridging selenolate ligands. Only two copper atoms are coordinated by 2,2′bipyridine. The corresponding copper(I) selenolate complex ( 5 ) forms a folded four-membered Cu₂Se₂ ring with μ₂-bridging selenolate ligands. The Cu? Cu distance of 2.52 Å is relatively short. In contrast to the reaction performed with 2,2′-bipyridine, addition of phenantroline to 1 respectively 2 yields a dinuclear complex [CuS(2,4,6-iPr₃C₆H₂)]₂(Phen)₂ ( 10 ). NMR spectroskopic and cryoscopic measurement of 4 show that this complex dissociates into smaller fragments in solution which undergo rapid exchange reactions. However, corresponding investigations performed on 5 indicate that the solid state structure is maintained in solution. The electrochemical behaviour of 4, 5 and 10 was studied in CH₂Cl₂ and in any case no reversible redox processes could be observed.     

New Thioantimonates(III) with Different Sb:S Ratios: Solvothermal Syntheses and Crystal Structures of [(C3H10NO)(C3H10N)][Sb8S13], [(C2H8NO)(C2H8N)(CH5N)][Sb8S13], [(C6H16N2)(C6H14N2)][Sb6S10], and [C8H22N2][Sb4S7]

Four new thioantimonates(III) with compositions [(C₃H₁₀NO)(C₃H₁₀N)][Sb₈S₁₃] ( 1 ) (C₃H₉NO = 1‐amino‐3‐propanol, C₃H₉N = propylamine), [(C₂H₈NO)(C₂H₈N)(CH₅N)][Sb₈S₁₃] ( 2 ) (C₂H₇NO = ethanolamine, C₂H₇N = ethylamine, CH₅N = methylamine), [(C₆H₁₆N₂)(C₆H₁₄N₂)][Sb₆S₁₀] ( 3 ) (C₆H₁₄N₂ = 1,2‐diaminocyclohexane) and [C₈H₂₂N₂][Sb₄S₇] ( 4 ) (C₈H₂₀N₂ = 1,8‐diaminooctane) were synthesized under solvothermal conditions. Compound 1 : triclinic space group P$\bar{1}$ , a = 6.9695(6) Å, b = 13.8095(12) Å, c = 18.0354(17) Å, α = 98.367(11), β = 96.097(11) and γ = 101.281(11)°; compound 2 : monoclinic space group P2₁/m, a = 7.1668(5), b = 25.8986(14), c = 16.0436(11) Å, β = 96.847(8)°; compound 3 : monoclinic space group P2₁/n, a = 11.6194(9), b = 10.2445(5) Å, c = 27.3590(18) Å, β = 91.909(6)°; compound 4 : triclinic space group P$\bar{1}$ , a = 7.0743(6), b = 12.0846(11), c = 13.9933(14) Å, α = 114.723(10), β = 97.595(11), γ = 93.272(11)°. The main structural feature of the two atoms thick layered [Sb₈S₁₃]^2– anion in 1 are large nearly rectangular pores with dimensions 11.2 × 11.7 Å. The layers are stacked perpendicular to [100] to form tunnels being directed along [100]. In contrast to 1 the structure of 2 contains a [Sb₈S₁₃]^2– chain anion with Sb₁₂S₁₂ pores measuring about 8.9 × 11.5 Å. Only if longer Sb–S distances are considered as bonding interactions a layered anion is formed. The chain anion [Sb₆S₁₀]^2– in compound 3 is unique and is constructed by corner‐sharing SbS₃ pyramids. Two symmetry‐related single chains consisting of alternating SbS₃ units and Sb₃S₃ rings are bound to Sb₄S₄ rings in chair conformation. Finally, in the structure of 4 the SbS₃ and SbS₄ moieties are joined corner‐linked to form a chain of alternating SbS₄ units and (SbS₃)₃ blocks. Neighboring chains are connected into sheets that contain relatively large Sb₁₀S₁₀ heterorings. The sheets are further connected by sulfur atoms generating four atoms thick double sheets.     

四甲基双硅桥联环戊二烯基稀土金属有机配合物的合成及[Me4Si2(C5H4)2Sm(μ-Cl)(THF)]2的晶体结构研究

四甲基双硅桥联环戊二烯基钠与无水三氯化稀土在THF溶剂中反应合成了标题配合物Me₄Si₂(C₅H₄)₂LnCl[Ln:3Nd,4Sm,5Gd,6Y]和配合物Me₄Si₂(C₅H₄):Ln(C₅H₅)(THF)n[Ln:1La,n=1;2Pr,n=0].通过元素分析、¹HNMR、13CNMR和MS确证了配合物的结构,在THF溶液中重结晶获得配合物4的单晶,x射线衍射证明晶体结构为二聚体,4为单斜晶系,空间群为P2₁/c,晶体学数据a=1.2982(3)nm,b=1.2269(3)nm,c=1.3681(2)nm,β=96.79(2)°,V=2.162(1)nm³,Z=2,D_x=1.53g/cm³,偏差因子R=0.068.     

[Co(N-(3-Aminopropyl)-1,3-propanediamine)(2-(Aminomethyl)pyridine) Cl][ZnCl_4]的一对差向异构体的合成及晶体结构

用过氧化物法合成了 [Co(3,3-tri)(amp)Cl][ZnCl4]的两个经式异构体,晶体结构解析表明两者互为差向异构体。其中反式异构体 (仲氢相对于 Cl)晶体属单斜晶系,空间群 C2/c, a=2.7663(7)nm, b=0.9505(1)nm, c=1.8288(4)nm,β =105.57(2)°, V=4.632(1)nm3, Dc=1.706g· cm-3, Z=8, F000=2432.00,μ (MoKα )=23.51cm-1, R=0.033, Rw=0.041;顺式异构体 (仲氢相对于 Cl)晶体属三斜晶系,空间群, a=1.0790(2)nm, b=1.1749(1)nm, c=0.8920(1)nm,α =90.73(1)°,β =109.573(9)°,γ =80.60(1)°, V=1.0500(2)nm3, Dc=1.71g· cm-3, Z=2, F000=548.00,μ (MoKα )=25.73cm-1, R=0.022, Rw=0.030。两异构体中 Co3＋为六配位,其差异仅表现在 3,3-tri仲胺上氢的取向不同。     

Synthesis,molecular and electronic structure of [ReCl2(N2COPh)(C4N2H4)(PPh3)2]

A new organodiazenido rhenium complex, [ReCl₂(N₂COPh)(C₄N₂H₄)(PPh₃)₂] has been obtained from the direct reaction of [ReCl₂(η²–N₂COPh–N′,O)(PPh₃)₂] with pyrazine in acetone. The complex has been characterized by spectroscopic methods and its structure determined using single-crystal X-ray diffraction techniques.     

Die Kristallstrukturen der Triarylzinkate [Mg2Br3(THF)6][ZnPh3] und [MgBr(THF)5][ZnMes3]

Crystal Structures of the Triarylzincates [Mg₂Br₃(THF)₆][ZnPh₃] and [MgBr(THF)₅][ZnMes₃] The title compounds were obtained from reactions of the phosphoraneiminato complex [ZnBr(NPMe₃)]₄ with excess Grignard reagents RMgBr (R = C₆H₅, 2,4,6-(CH₃)₃–C₆H₂) in THF solution. According to X-ray structure determinations the [ZnR₃]^– ions contain zinc atoms which are coordinated in a planar fashion with Zn–C distances of 200.7 pm (R = Ph) and 203.4 pm (R = Mes) in average.     

N(B(NMe2)2)(Si(NMe2)3)(Ti(NMe2)3), [N(Si(NMe2)3)(Ti(NMe2)2)]2 und N(SiMe3)(Si(NMe2)3)(Ti(NMe2)3) — Synthese und Charakterisierung neuer molekularer Einkomponentenvorläufer für nitridische und carbonitridische Keramiken

N(B(NMe₂)₂)(Si(NMe₂)₃) (Ti(NMe₂)₃), [N(Si(NMe₂)₃)(Ti(NMe₂)₂)]₂ und N(SiMe₃)(Si(NMe₂)₃)(Ti(NMe₂)₃) — Synthesis and Characterization of New Molecular Single-source Precursors for Nitride and Carbonitride Ceramics Synthesis and spectroscopic data of the title compounds are reported. [N(Si(NMe₂)₃)(Ti(NMe₂)₂)]₂ crystallizes in the space group P1 , a = 8.406(7), b = 10.673(8), c = 10.872(6) Å, α = 68.45(4)°, β = 71.72(4)°, γ = 78.11(7)°, 2 877 diffractometer data (F_o ? 2σF_o), R = 0.051. The compound is characterized by a planar four-membered Ti₂N₂-ring with exocyclic tris(dimethylamino)silyl substituents attached to the nitrogen atoms of the ring.     

Hydrogenation of C=C and C=N Bonds of the Amide-Imine Ligand in the Metal Coordination Sphere in the Reaction of Yttrium Bis(alkyl) Complex [2,6-iso-Pr2C6H3NC(=CH2)C(Me)=NC6H3-iso-Pr2-2,6]Y(CH2SiMe3)2(THF) with Molecular Hydrogen

Russian Journal of Coordination Chemistry - On treatment of the yttrium bis(alkyl) complex [ArNC(=CH2)C(Me)=NAr]Y(CH2SiMe3)2(THF) (I, Ar = C6H3-iso-Pr2-2.6) containing an amide-imine ligand, with...     

Synthesis,characterization, and DNA-binding of [Co(phen)2(CPIA)]3+, [Co(phen)2(BIP)]3+, and [Co(phen)2(CIP)]3+

Three ligands, 2-(3-(carboxymethyl)-1,10-phenanthroline-[5,6-d]imidazole-1-yl)acetate (CPIA), 2-(benzo[d][1,3]dioxol-4-yl)-1H-imidazo[4,5-f][1,10]phenanthroline (BIP), and 2-(9H-carbazol-3-yl)-1H-imidazo[4,5-f][1,10]phenanthroline (CIP), and their complexes, [Co(phen)₂(CPIA)]³⁺ (1) (phen = 1,10-phenanthroline), [Co(phen)₂(BIP)]³⁺ (2), and [Co(phen)₂(CIP)]³⁺ (3), have been synthesized and characterized. Binding of the three complexes with calf thymus DNA (CT-DNA) has been investigated by spectroscopic methods, cyclic voltammetry, and viscosity measurements. The three complexes bind to DNA through an intercalative mode, and the size and shape of the intercalative ligands have significant effects on the binding affinity of complexes to CT-DNA.     

Phosphaniminato‐Cluster von Eisen. Die Kristallstrukturen von [FeCl(NPEt3)]4, [Fe(C=C–SiMe3)(NPEt3)]4 und [Fe3Cl4{NP(NMe2)3}3]

Phosphoraneiminato Cluster of Iron. The Crystal Structures of [FeCl(NPEt₃)]₄, [Fe(C=C–SiMe₃)(NPEt₃)]₄, and [Fe₃Cl₄{NP(NMe₂)₃}₃] The reaction of iron dichloride with the silylated phosphaneimine Me₃SiNPEt₃ in the presence of potassium fluoride at 165 ?C leads to the phosphoraneiminato complex [FeCl(NPEt₃)]₄ ( 1 ). Compound 1 forms black, moisture and oxygen sensitive crystals. According to the crystal structure analysis 1 has a heterocubane structure, in which the iron and the nitrogen atoms of the NPEt₃^– groups occupy the corners of a distorted cube and form Fe–N–Fe bond angles of 83.1? and N–Fe–N angles of 96.5?. This results in significantly short Fe…Fe contacts of 272.9 pm. The results of magnetic susceptibility measurements in the range of temperatures from 1.8 to 293 K and the ⁵⁷Fe‐Mössbauer spectra in the range of temperatures from 2 to 300 K are reported. Compound 1 reacts with the lithiated acetylenes LiC=C–CMe₃ and LiC=C–SiMe₃ in n‐hexane to form the iron‐organic derivatives [Fe(C=C–R)(NPEt₃)]₄ [R = CMe₃ ( 2 a ), R = SiMe₃ ( 2 b )] keeping the heterocubane structure. Compounds 2 a and 2 b form crystals which are very reactive and also black. According to the crystal structure analysis 2 b has a Fe₄N₄ heterocubane structure which is less distorted than that in 1 with bond angles Fe–N–Fe of 85.5? and N–Fe–N of 94.2?. This leads to the longer Fe…Fe contacts of 281.4 pm. With the dimethylamido derivative Me₃SiNP(NMe₂)₃ iron dichloride reacts under conditions similar to those in the synthesis of 1 to form the dark green mixed‐valenced Fe^II/Fe^III cluster [Fe₃Cl₄{NP(NMe₂)₃}₃] ( 3 ). According to the crystal structure analysis the three iron atoms in 3 are connected via one μ₃‐N atom of a NP(NMe₂)₃^– ligand, via two μ‐N atoms of the two remaining phosphoraneiminato ligands, and via one μ‐Cl atom to form an incomplete heterocubane skeleton.     

Zinc(II) complexes derived from imidazo[1,2-a]pyridin-2-ylacetic acid (HIP-2-ac): [Zn(IP-2-ac)2(H2O)] and unexpectedly, [Zn3(IP-2-ac)6(H2O)]·11H2O

Two zinc(II) complexes based on imidazo[1,2-a]pyridin-2-ylacetate (IP-2-ac), [Zn(IP-2-ac)₂(H₂O)] (1) and [Zn₃(IP-2-ac)₆(H₂O)]·11H₂O (2), were synthesized and characterized by single-crystal X-ray diffraction. In both 1 and 2, zinc(II) ions are five-coordinate with N₂O₃ donor set, best described as a distorted trigonal-bipyramidal geometry. In 1, two IP-2-ac ligands chelate zinc(II) through a N,O donor set, whereas in 2, both bidentate and μ-bridging binding modes of IP-2-ac are observed. The crystal of 1 comprises discrete Zn(IP-2-ac)₂(H₂O) coordination entities combined into layers by hydrogen bonds. Inter-layer stabilization of the 3-D crystal lattice is provided by weak C–H?O contacts and π?π interactions. The structure of 2 consists of discrete trinuclear Zn₃(IP-2-ac)₆(H₂O) coordination entities joined into crystal lattice by multiple water molecules.

Compound 1 was characterized by FTIR and FT-Raman spectroscopy, and in terms of thermal stability. Furthermore, its antibacterial activity was tested against selected gram-positive, gram-negative bacteria, and Candida albicans yeast and compared with activity of previously reported [M(IP-2-ac)₂(H₂O)₂]·2H₂O (M = Co, Ni, Mn, Cd) complexes.