Studies directed toward the synthesis of the eremantholides 1.Preparation of a ring a/b model system via a conjugate addition-acylation protocol

Synthesis of a model A/B ring subunit of eremantholide A (1) is described.     

Complete assignments of 1H and 13C NMR data for trypanocidal eremantholide C oxide derivatives

The chemical transformations of eremantholide C (1), a trypanocidal sesquiterpene lactone isolated from Lychnophora trichocarpha Spreng., gave five new oxide derivatives: 3'-hydroxyeremantholide C (2), 1'-formyleremantholide C (3), 1'-carboxyeremantholide C (4), 1'-carbomethoxyeremantholide C (5) and sodium 1'-carboxylate of eremantholide C (6). The (1)H and (13)C NMR data of all these derivatives were assigned based on 1D and 2D techniques. The derivatives were evaluated against Y and CL strains of Trypanosoma cruzi. All of them were inactive against the Y strain. Compounds 2 and 5 displayed 100% activity on the CL strain while compounds 4 and 6 were partially active on the CL strain.     

Detailed 1H and 13C NMR structural assignment and relative stereochemistry determination for three closely related sesquiterpene lactones

A complete analysis of (1)H and (13)C NMR spectra of the trypanocidal sesquiterpene lactone eremantholide C and two of its analogues is described. These structurally similar sesquiterpene lactones were submitted to (1)H NMR, (13)C {(1)H} NMR, gCOSY, gHSQC, gHMBC, J-resolved and DPFGSE-NOE NMR techniques. The detailed analysis of those results, correlated to some computational calculations (molecular mechanics), led to the total and unequivocal assignment of all (1)H and (13)C NMR data. The determination of all (1)H/(1)H coupling constants and all signal multiplicities, together with the elimination of previous ambiguities were also achieved.     

Mixed-ligand complex formation equilibria of CuII with biguanide in presence of glycine as the auxiliary ligand

Equilibrium study on the mixed ligand complex formation of Cu^II with biguanide(Bg) and glycine (HG), indicated the formation of the complexes: Cu(Bg)²⁺, Cu(Bg) ₂ ²⁺ , Cu(Bg-H)(Bg)+, Cu(Bg-H)₂, Cu(Bg)(OH)⁺, Cu(Bg-H)(OH); Cu(G)⁺, Cu(G)(OH), Cu(G)₂; Cu(G)(Bg)⁺, Cu(G)(Bg-H); (G)Cu(Bg)Cu(G)²⁺, (G)Cu(Bg-H)Cu(G)⁺, and (G)Cu(Bg-2H)Cu(G). From the deprotonation constants of coordinated biguanide (Bg) in the complexes Cu(Bg)(OH)⁺, Cu(Bg-H)(Bg)⁺ and Cu(G)(Bg)⁺, the Lewis basicities of the coordinated ligand species (Bg-H)^-, OH^- and glycinate (G^-) were found to be of the order: (Bg-H)^-≫ OH^- > G^-. Bridging (N¹-N⁴, N²-N⁵) tetradentate mode of coordination by biguanide species Bg, (Bg-H)^- and (Bg2H)^2- was indicated from the occurrence of biguanide-bridged dinuclear mixed ligand complexes (G)Cu(Bg)Cu(G)²⁺, (G)Cu(Bg-H)Cu(G)⁺, (G)Cu(Bg-2H)Cu(G) in the complexation equilibria.     

SYNTHESIS OF A DINUCLEAR YLID COMPLEX DERIVED FROM P(OPh)3: CRYSTAL STRUCTURES OF [Cp2Fe2(CO)2(μ-CO) (μ-CHP(OPh)3)+][BF4 −] AND [Cp2Fe2(CO)2 (μ-CO)(μ-CHPPh3)+][BF4 −]

Abstract

[Cp₂Fe₂(CO)₂(μ-CO)(μ-CHP(OPh)₃)⁺][BF^? ₄] crystallizes in the centrosymmetric monoclinic space group P2₁/n with a = 12.553(7) Å, b = 16.572(11) Å, c = 15.112(8) Å, β = 100.00(4)°, V = 3096(3) ų and D(calcd.) = 1.579 g/cm³ for Z = 4. The structure was refined to R(F) = 5.83% for 1972 reflections above 4σ(F). The cation contains two CpFe(CO) fragments linked via an iron—iron bond (Fe(1)—Fe(2) = 2.544(3)Å), a bridging carbonyl ligand (Fe(1)—C(4) = 1.918(1) Å, Fe(2)—C(4) = 1.946(12)Å) and a bridging CHP(OPh)₃ ligand (Fe(1)—C(1) = 1.980(9)Å, Fe(2)—C(1) = 1.989(8)Å). Distances within the μ-CHP(OPh)₃ moiety include a rather short carbon—phosphorus bond [C(1)—P(1) = 1.680(10)Å] and P—O bond lengths of 1.550(7)–1.579(6)Å. The crystal is stabilized by a network of F…H—C interactions involving the BF^? ₄ anion.

[Cp₂Fe₂(CO)₂(μ-CO)(μ-CHPPh₃)⁺][BF^? ₄], which differs from the previous compound only in having a μ-CHPPh₃ (rather than μ-CHP(OPh)₃) ligand, crystallizes in the centrosymmetric monoclinic space group P2₁/c with a = 11.248(5)Å, b = 13.855(5)Å, c = 18.920(7)Å, β = 96.25(3)°, V = 2931(2)ų and D(calcd.) = 1.559 g/cm³ for Z = 4. This structure was refined to R(F) = 4.66% for 1985 reflections above 4σ(F). Bond lengths within the dinuclear cation here include Fe(1)-Fe(2) = 2.529(2)Å, Fe(1)—C(3) = 1.904(9) Å and Fe(2)—C(3) = 1.911(8) Å (for the bridging CO ligand) and Fe(1)—C(1P) = 1.995(6) Å and Fe(2)—C(1P) = 1.981(7) Å (for the bridging CHPPh₃ ligand). Distances within the μ-CHPPh₃ ligand include a longer carbon—phosphorus bond [C(1P)—P(1) = 1.768(6)Å] and P(1)—C(phenyl) = 1.797(7)–1.815(8) Å.     

Synthesis and Characterization of Partially Substituted at Lower Rim Phosphorus Containing Calix(4)arenes

The synthesis and characterization of several new phosphorus-containing partially lower rim substituted derivatives of 5,11,17,23-tetra(t-butyl) calix(4)arene (I) and 5,11,17,23-tetra(t-octyl)calix(4)arene (II), namely 5,11,17,23-tetra(t-butyl)-25,27-dihydroxy-26,28-bis(diphenylphosphinoyl-oxy) calix(4)arene (IV); 5,11,17,23-tetra(t-butyl)-25-hydroxy-26,27,28-tris(tetramethyldiamido-phosphinoyl-oxy) calix(4)arene (Vb); 5,11,17,23-tetra(t-butyl)-25,27-dihydroxy-26,28-bis(dimethyl-phosphinoyl-methoxy) calix(4)arene (VI); 5,11,17,23-tetra (t-octyl)-25,27-dihydroxy-26,28-bis(dimethyl-phosphinoyl-methoxy) calix(4)arene (VII) are reported. The structure of the synthesized calix(4)arene derivatives are identified and confirmed by elemental analysis, IR, ¹H, ¹³C, ³¹P{¹H} NMR spectroscopy and mass spectrometry as and X-ray crystallographic analysis of 5,11,17,23-tetra(t-butyl)-25,27-dihydroxy-26,28-bis(dimethyl-phosphinoyl-methoxy) calix(4)arene VI. According to the NMR spectra, all calix(4)arenes are in cone conformation.     

Solvent effects on oxygen atom transfer reaction between manganese(V)-oxo corrole and alkene

Pseudo-first order reaction rate constants of 5,10,15-tris（pentafluorophenyl）corrole Mn（V）-oxo (F₁₅CMn（V）-oxo),5,15-bis（pentafluorophenyl）-10-（phenyl）corrole Mn（V）-oxo(F₁₀CMn（V）-oxo),5,15- bis（phenyl）-10-（pentafluorophenyl）corrole Mn（V）-oxo（F₅CMn（V）-oxo） and 5,10,15-tris（phenyl）corrole Mn（V）-oxo（F₀CMn（V）-oxo） with a series of alkene substrates in different solvents were determined by UV-vis spectroscopy.The results indicated that the oxygen atom transfer pathway between Mn（V）-oxo corrole and alkene is solvent-dependent.     

Reactions of RSe− (R = Me,Ph) Groups in [RSeFe(CO)4I and [RSeCr(CO)5−]

The anionic [MeSeFe(CO)₄] and [MeSeCr(CO)₅] complexes were synthesized by reaction of [PPN][HFe(CO)₄] and [PPN][HCr(CO)₅] with MeSeSeMe respectively via nucleophilic cleavage of the Se-Se bond. The ease of cleavage of the Se-Se bond follows the nucleophilic strength of metal-hydride complexes. Methylation of [RSeCr(CO)₅^?] by the soft alkylating agent MeI resulted in the formation of neutral (MeSeMe)Cr(CO)₅ in THF at 0°C. In contrast, the [ICr(CO)₅^?] was isolated at ambient temperature. Reaction of [MeSeFe(CO)₄^?] or [MeSeCr(CO)₅^?] with HBF₄ yielded (CO)₃Fc(μ-SeMe)₂Fe(CO)₃ dimer and anionic [(CO )₅Cr (μ-SeMe)Cr(CO)₅^?] respectively, and no neutral (HSeMe)Fe(CO)₄ and (HSeMe)Cr(CO)₅ were detected spectrally (IR) even at low temperature. Reaction of NOBF₄ or [Ph₃C][BF₄] and [MeSeCr(CO)₅^?] resulted in the neutral monodentate (MeSeSeMe)Cr(CO)₅ complex. Addition of 1 equiv CpFe(CO)₂I to 2 equiv [MeSeCr(CO)₅^?] gave CpFe(CO)₂(SeMe) and the anionic [(CO)₅Cr(μ-SeMe)Cr(CO)₅^?] in THF at ambient temperature.     

Dibenzophenoxazon-(5)-derivate als Neutralisationsindicatoren in wasserfreier Essigs?ure

Zusammenfassung Die relativen Basizitätskonstanten von 5H-Dibenzo(a,h)phenoxazon-(5) (I) (K=3,2 · 10^–2), 5H-Dibenzo(a,j)phenoxazon-(5) (II) (K=6,5 · 10^–2), 9-(N-1-Naphthylamino)-5H-dibenzo(a,j)phenoxazon-(5) (III) (K=1,12), 9-(N-2-Naphthylamino)-5H-dibenzo(a, j)phenoxazon-(S) (IV) (K=1,22), 9-Anilino-5H-dibenzo(a,j) phenoxazon-(5) (V) (K=1,28) und 9-(p-Tolylamino)-5H-dibenzo(a,j)phenoxazon-(5) (VI) (K=1,45) wurden für das Puffersystem Acetat-Antipyrinperchlorat in wasserfreier Essigsäure bestimmt. Die Verbindungen II, V und VI wurden zur visuellen Indikation von Titrationen schwacher Basen mit Perchlorsäure in wasserfreier Essigsäure benutzt. Mit Indicator II können Basen mit pK_a(H₂O)-Werten von 2–4 und mit den Indicatoren V und VI stärkere Basen mit pK_a(H₂O)-Werten von 4–7 bestimmt werden.

---

Dibenzophenoxazone-(5)-derivatives as neutralisation indicators in non-aqueous acetic acid

The relative basicity constants of 5H-dibenzo(a,h)phenoxazone-(5) (I) (K=3.2×10^–2), 5H-dibenzo(a,j)phenoxazone-(5) (II) (K=6.5×10^–2), 9-(N-1-naphthylamino)-5H-dibenzo(a,j)phenoxazone-(5) (III) (K=1.12), 9-(N-2-naphthylamino)-5H-dibenzo(a,j)phenoxazone-(5) (IV) (K=1.22), 9-anilino-5H-dibenzo(a,j)phenoxazone-(5) (V) (K=1.28) and 9-(p-tolylamino)-5H-dibenzo(a,j)phenoxazone-(5) (VI) (K=1.45) have been determined with respect to the buffer system antipyrine acetate-antipyrine perchlorate in non-aqueous acetic acid. The compounds II, V and VI were employed for visual indication of titrations of weak bases with perchloric acid in non-aqueous acetic acid. Indicator II is convenient for the titration of bases with pK _a (H₂O) values 2–4 and indicators V and VI for bases with pK_a(H₂O) values 4–7.

     

Synthesis,characterization and biological properties of novel ON donor bidentate Schiff bases and their copper(II) complexes

Four novel ON donor Schiff bases (E)-3-((4-phenoxyphenylimino)methyl)benzene-1,2-diol (HL₁),(E)-3-((4-(4-biphenyloxy)phenyliminomethyl)benzene-1,2-diol (HL₂), (E)-3-((4-naphthoxyphenylimino)methyl)benzene-1,2-diol (HL₃), (E)-3-((4-(2-naphthoxy)phenylimino)methyl)benzene-1,2-diol (HL₄) and their copper(II) complexes bis((E)-3-((4-phenoxyphenylimino)methyl)benzene-1,2-diol) copper(II) (Cu(L₁)₂) bis((E)-3-((4-(4-biphenyloxy)phenylimino)methyl)benzene-1,2-diol) copper(II) (Cu(L₂)₂), bis((E)-3-((4-naphthoxyphenylimino)methyl)benzene-1,2-diol) copper(II) (Cu(L₃)₂), bis((E)-3-((4-(2-naphthoxy)phenylimino)methyl)benzene-1,2-diol) copper(II) (Cu(L₄)₂) have been synthesized and characterized by spectroscopic (FTIR, NMR, UV–visible) and elemental analysis. The crystal structures of HL₁, HL₂, HL_3, and HL₄ have been determined, which reveal intramolecular N-H?O (HL₁, HL₂, HL_3, and HL₄) hydrogen bonds in the solid state. Keto-amine and enol-imine tautomerism is exhibited by the Schiff bases in solid and solution states. The Schiff bases and their copper(II) complexes have been screened for their biological activities. In antimicrobial assays (antibacterial and antifungal), HL₄ showed promising results against all strains through dual inhibition property while the rest of the compounds showed activity against selective strains. On the other hand, in cytotoxic, DPPH, and inhibition of hydroxyl (OH) free radical-induced DNA damage assays, the results were found significantly correlated with each other, i.e. the ligands HL₁ and HL₂ showed moderate activity while their complexes Cu(L₁)₂ and Cu(L₂)₂ exhibited prominent increase in activity. As the results of these assays are supporting each other, it represents the strong positive correlation and antioxidant nature of investigated compounds.     

1,1-Dithiooxalsäurederivate als Liganden in Übergangsmetallkomplexen: Struktur von O-Methyl-1,1-dithiooxalato-bis(triphenylphosphin)kupfer(I) und -silber(I)

1,1-Dithiooxalic Acid Derivatives as Ligands in Transition Metal Complexes: Structure of O-Methyl-1,1-dithiooxalato-bis(triphenylphosphine)copper(I) and silver(I) Despite O-Alkyl-1,1-dithiooxalates are also tetradentate thioligands their tendency towards the formation of multi-nuclear bridged chelates as found for the basic 1,1-dithiooxalate does practically not exist because of derivatisation. The reaction with triphenylposphinemetal(I)-halogenides yields defined mono-nuclear mixed ligand complexes: O-Methyl-1,1-dithiooxalato-bis(triphenylphosphine)copper(I) ( 2 ) and silver(I) ( 1 ). X-ray analysis shows that both complexes ( 1 and 2 ) are isostructural and crystallize in the monoclinic space group P2₁/n: (Ph₃P)₂Ag(S₂C₂O₂Me) ( 1 ) with a = 12.794(1), b = 21.314(4), c = 13.560(1) Å, β = 97.983(6)°, and (Ph₃P)₂Cu(S₂C₂O₂Me) ( 2 ) with a = 12.622(1), b = 21.196(2), c = 13.426(1) Å, β = 96.533(7)°. These complexes are the first authentic examples of exclusively end-on coordinated thiooxalate.     

COPPER(I) COMPLEXES WITH N-(P-NITROPHENYL)-N′-ALKOXYCARBONYLTHIOUREA: SYNTHESES AND CRYSTAL STRUCTURES OF [Cu(H2net)2CI] · CH2CI2 AND [Cu(H2nmt)2CI]2·(CHCI3)2

Abstract

Two copper(I) complexes, [Cu(H₂net)₂Cl] · CH₂Cl₂ (1) and [Cu(H₂nmt)₂Cl]₂ · (CHCl₃)₂ (2), were synthesized by the reaction of CuCl₂ · 2H₂O with N-(p-nitrophenyl)-N′-(ethoxycarbonyl)-thiourea (H₂net) and N-(p-nitrophenyl)-N′-(methoxycarbonyl)-thiourea(H₂nmt), respectively. Both complexes crystallize in the monoclinic space group C2/c. For complex 1, a = 29.52(2), b=13.920(6), c = 14.873(3)Å; β= 101.75(2)°, V = 5984(4) ų, Z = 8 and R = 0.053; for complex 2, a = 30.68(1), b = 13.369(4), c = 14.226(7) Å, β = 99.52(4)°. V = 5754(4) ų, Z = 4 and R = 0.063. In complex 1, two H₂net molecules are bonded to Cu(I) atom through two S atoms forming a mononuclear complex with trigonal geometry for the Cu(I) ion [Cl(1)-Cu-S(1)=118.54(7), Cl(1)-Cu-S(2)=119.70(7), S(1)-Cu-S(2)=112.17(8)°, Cu-S(1) = 2.251(2), Cu-S(2) = 2.255(2), Cu-Cl(1) = 2.263(2) Å]. Complex 2 is a dimer formed by long Cu-S interactions [Cu-S* = 2.607(3) Å] from adjacent twc H₂nmt molecules; the Cu(I) ion has distorted tetrahedral coordination [Cl(1)-Cu-S(1) = 119.8(1), Cl(1)-Cu-S(2)=120.0(1), S(1)-Cu-S(2)=108.85(9)°] with unequal Cu-S [2.268(2), 2.247(2)Å] and Cu-Cl(1) [2.255(2)Å] bonds.     

Comparison of the properties of waterborne polyurethane-ureas containing different triblock glycols for water vapor permeable coatings

Four types of triblock glycols [(CL)_4.5-PEG-(CL)_4.5, (CL)_4.5-PTAd-(CL)_4.5, (CL)_4.5-PTMG-(CL)_4.5, and (CL)_4.5-PPG-(CL)_4.5, Mn=3,000] were synthesized by end-capping reactions of -caprolactone (CL) and poly(ethylene) glycol (PEG, Mn=2,000), poly(tetramethylene adipate) glycol (PTAd, Mn=2,000), poly(tetramethylene) glycol (PTMG, Mn=2,000), or polypropylene glycol (PPG, Mn=2,000)]. Waterborne polyurethanes (WBPUs) were prepared by polyaddition reaction using 4,4-dicyclohexylmethane diisocyanate (H₁₂MDI), 2,2-bis (hydromethyl) propionic acid (DMPA), ethylene diamine (EDA), triethyl amine (TEA), and the triblock glycol. Studies have been conducted on the effects of triblock glycol type on the colloidal properties of dispersion, the hardness and mechanical properties of WBPU films, the water vapor permeability (WVP), and water resistance (WR) of WBPU-coated nylon fabrics. The WVP (%WVP based on control nylon fabric) of WBPU-coated nylon fabrics based on (CL)_4.5-PEG-(CL)_4.5, (CL)_4.5-PTAd-(CL)_4.5, (CL)_4.5-PTMG-(CL)_4.5 and (CL)_4.5-PPG-(CL)_4.5 were 3,975(81), 3,115(62), 3,124(64), and 2,569(52) g/m² day (%), respectively. However, the WBPU based on (CL)_4.5-PEG-(CL)_4.5 was not applicable for coating material, because its dispersion and film had relatively high viscosity (3,000 cps at 50°C) and low mechanical properties, respectively. In this work, the triblock glycols (CL)_4.5-PTMG-(CL)_4.5 and (CL)_4.5-PTAd-(CL)_4.5 were found to be desirable glycols for water vapor permeable coating materials.     

1,2‐Dithioquadratato‐ und 1,2‐Dithiooxalatoindate(III)

Indium(III) chloride forms in water with potassium 1,2‐dithiooxalate (dto) and potassium 1,2‐dithiosquarate (dtsq) stable coordination compounds. Due to the higher bridging ability of the 1,2‐dithiooxalate ligand in all cases only thiooxalate bridged binuclear complexes were found. From 1,2‐dithioquadratate with an identical donor atom set mononuclear trischelates could be isolated. Five crystalline complexes, (BzlMe₃N)₄[(dto)₂In(dto)In(dto)₂] ( 1 ), (BzlPh₃P)₄[(dto)₂In(dto)In(dto)₂] ( 2 ), (BzlMe₃N)₃[In(dtsq)₃] ( 3 ), (Bu₄N)₃[In(dtsq)₃] ( 4 ) and (Ph₄P)[In(dtsq)₂(DMF)₂] ( 5 ), have been isolated and characterized by X‐ray analyses. Due to the type of the complex and the cations involved these compounds crystallize in different space groups with the following parameters: 1 , monoclinic in P2₁/c with a = 14.4035(5) Å, b = 10.8141(5) Å, c = 23.3698(9) Å, β = 124.664(2)°, and Z = 2; 2 , triclinic in P with a = 11.3872(7) Å, b = 13.6669(9) Å, c = 17.4296(10) Å, α = 88.883(5)°, β = 96.763(1)°, γ = 74.587(5)°, and Z = 1; 3 , hexagonal in R3 with a = 20.6501(16) Å, b = 20.6501(16) Å, c = 19.0706(13) Å and Z = 6; 4 , monoclinic in P2₁/c with a = 22.7650(15) Å, b = 20.4656(10) Å, c = 14.4770(9) Å, β = 101.095(5)°, and Z = 4; 5 , triclinic in P with a = 9.2227(6) Å, b = 15.3876(9) Å, c = 15.5298(9) Å, α = 110.526(1)°, β = 100.138(1)°, γ = 101.003(1)°, and Z = 2.     

Phthalocyaninate und Tetraphenylporphyrinate von hochkoordiniertem ZrIV/HfIV mit Hydroxo‐, Chloro‐, (Di)Phenolato‐, (Hydrogen)Carbonato‐ sowie (Amino)Carboxylato‐Liganden

Phthalocyaninates and Tetraphenylporphyrinates of High Co‐ordinated Zr^IV/Hf^IV with Hydroxo, Chloro, (Di)Phenolato, (Hydrogen)Carbonato, and (Amino)Carboxylato Ligands Crystals of tetra(n‐butyl)ammonium cis‐tri(phenolato)phthalocyaninato(2‐)zirconate(IV) ( 2 ) and ‐hafnate(IV) ( 1 ), di(tetra(n‐butyl)ammonium) cis‐di(tetrachlorocatecholato(O, O')phthalocyaninato(2‐)zirconate(IV) ( 3 ), and cis‐(di(μ‐alaninato(O, O')di(μ‐hydroxo))di(phthalocyaninato(2‐)zirconium(IV)) ( 12 ) have been isolated from tetra(n‐butyl)ammonium hydroxide solutions of cis‐di(chloro)phthalocyaninato(2‐)zirconium(IV) and ‐hafnium(IV), respectively, and the corresponding acid in polar organic solvents. Similarly, with cis‐di(chloro)tetraphenylporphyrinato(2‐)zirconium(IV), ^cis[Zr(Cl)₂tpp] as precursor crystalline tetra(n‐butyl)ammoniumcis‐tetrachlorocatecholato(O, O')hydrogentetrachlorocatecholato(O)tetraphenylporphyrinato(2‐)zirconate(IV) ( 4 ), cis‐hydrogencarbonato(O, O')phenolatotetraphenylporphyrinato(2‐)zirconium(IV) ( 6 ), cis‐di(benzoato(O, O'))tetraphenylporphyrinato(2‐)zirconium(IV) ( 11 ), and cis‐tetra(μ‐hydroxo)di(tetraphenylporphyrinato(2‐)zirconium(IV)) ( 13 ) with a cis‐arrangement of the symmetry equivalent μ‐hydroxo ligands, and from di(acetato)tetraphenylporphyrinato(2‐)zirconium(IV) the corresponding trans‐isomer ( 14 ) have been prepared. The endothermic dehydration at 215 °C of 13/14 yields μ‐oxodi(μ‐hydroxo)di(tetraphenylporphyrinato(2‐)zirconium(IV)) ( 15 ). 15 also precipitates on dilution of a solution of ^cis[Zr(X)₂tpp] (X = Cl, OAc) in dmf/(ⁿBu₄N)OH with water, while on prolonged standing of this solution on air tri(tetra(n‐butyl)ammonium) cis‐(^nido〈di(carbonato(O, O'))undecaaquamethoxide〉tetraphenylporphyrinato(2‐)zirconate(IV) ( 7 ) crystallizes, in which Zr^IV coordinates a supramolecular nestlike ^nido〈(O₂CO)₂(H₂O)₁₁OCH₃〉^5— cluster anion stabilised by hydrogen bonding in a nanocage of surrounding (ⁿBu₄N)⁺ cations. On the other hand, ^cis[Zr(Cl)₂pc] forms with (Et₄N)₂CO₃ in dichloromethane di(tetraethylammonium) cis‐di(carbonato(O, O')phthalocyaninato(2‐)zirconate(IV) ( 5 ). ^cis[Zr(Cl)₂tpp] dissolves in various O‐donor solvents, from which cis‐di(chloro)dimethylformamidetetraphenylporphyrinato(2‐)zirconium(IV) ( 8 ), cis‐di(chloro)dimethylsulfoxidetetraphenylporphyrinato(2‐)zirconium(IV) ( 9 ), and a 1:1 mixture ( 10 ) of cis‐di(chloro)dimethylsulfoxidetetraphenylporphyrinato(2‐)zirconium(IV) ( 10a ) and cis‐chlorodi(dimethylsulfoxide)tetraphenylporphyrinato(2‐)zirconium(IV) chloride ( 10b ) crystallize. All complexes contain solvate molecules in the solid state, except 3 . Zr^IV/Hf^IV is directed by ∼1Å out of the plane of the tetrapyrrolic ligand (pc, tpp) towards the mutually cis‐coordinated axial ligands. In the more concavely distorted phthalocyaninates, Zr^IV is mainly eight‐coordinated and in the tetraphenylporphyrinates seven‐coordinated. The octa‐coordinated Zr atom is in a distorted quadratic antiprism, and the hepta‐coordinated one is in a square‐base‐trigonal‐cap cooordination polyhedron. In most tpp complexes, the Zr atom is displaced by up to 0.3Å out of the centre of the coordination polyhedron towards the tetrapyrrolic ligand. In 13/14 , both antiprisms are face shared by an O₄ plane, and in 12 they are shared by an O₂ edge and the O atoms of the bridging aminocarboxylates, the dihedral angle between the O₄ planes of both antiprisms being 50.1(1)°. The mean Zr‐N_p distance is 0.05Å longer in the pc complexes than in the tpp complexes (d(Zr‐N_p)_pc = 2.31Å). In the monophenolato complexes, the mean Zr‐O distance (∼2.00Å) is shorter than in the complexes with other O‐donor ligands (d(Zr‐O)_pc = 2.18Å; d(Zr‐O)_tpp = 2.21Å); the Zr‐Cl distances vary between 2.473(1) and 2.559(2)Å (d(Zr‐Cl)_tpp = 2.51Å). d(C‐O_exo) = 1.494(4)Å in the bidentate hydrogencarbonato ligand in 6 is 0.26Å longer than in the bidentate carbonato ligands in 5 and 7 . 9 and 10a are rotamers slightly differing by the orientation of the axial ligands with respect to the tpp ligand. In 1—4, 6 , and 11 the phenolato, catecholato, and benzoato ligands, respectively, are in syn‐ and/or anti‐conformations with respect to the plane of the macrocycle. π‐Dimers with modest overlap of the neighbouring macrocyclic rings are observed in 5, 6, 8, 9, 10b, 12 , and 14 . The common UV/Vis spectroscopical and vibrational properties of the new phthalocyaninates and tetraphenylporphyrinates scarcely reflect their rich structural diversity.     

Mixed chelates of some trivalent lanthanide ions containing (trans-1,2-cyclhexylenedinitrilo)tetraacetate and norleucinate

Summary Formation constants of mixed chelates with (trans-1,2-cyclohexylenedinitrilo)tetra-acetate (DCTA) as primary ligand and norleucinate (nle) as secondary ligand with metal ions La(III), Ce(III), Pr(III), Sm(III), Gd(III), Tb(III), Dy(III), Er(III), and Yb(III) have been determined by the modified potentiometricpH titration method of Irving-Rossotti in aqueous medium at (295±1) K and fixed ionic strength of =0.1M (NaClO₄). Formation constants of binary complexes of the metal ions with the secondary ligand have also been determined under identical conditions. The mixed chelates were found to be more stable than the binary ones. The order of stabilities in terms of metal ions is La(III)Gd(III)

Gemischte Chelate einiger dreiwertiger Lanthanidenionen mit (trans-1,2-Cyclohexylendinitril)tetraacetat und Norleucinat

Zusammenfassung Es wurden die Komplexbildungskonstanten gemischter Chelate mit (trans-1,2-Cyclohexylendinitril)tetraacetat als Primärkomponente und Norleucinat als Sekundärkomponente mit den Metallionen La(III), Ce(III), Pr(III), Sm(III), Gd(III), Tb(III), Dy(III), Er(III) und Yb(III) mittels einer modifizierten potentiometrischen Titrationsmethode nach Irving-Rossotti in wäßrigem Medium bei (295±1) K und einer konstanten Ionenstärke von =0.1M (NaClO₄) bestimmt. Die Bildungskonstanten der binären Komplexe der Metallionen mit dem Sekundärliganden wurden ebenfalls unter identen Bedingungen bestimmt. Es wurde festgestellt, daß die gemischten Chelate stabiler sind als die binären. Die Stabilitätsreihenfolge bezüglich der Metallionen ist La(III)Gd(III)     

Porphyrin N-Pincer Pd(II)-Complexes in Water: A Base-Free and Nature-Inspired Protocol for the Oxidative Self-Coupling of Potassium Aryltrifluoroborates in Open-Air

Metalloporphyrins (and porphyrins) are well known as pigments of life in nature, since representatives of this group include chlorophylls (Mg-porphyrins) and heme (Fe-porphyrins). Hence, the construction of chemistry based on these substances can be based on the imitation of biological systems. Inspired by nature, in this article we present the preparation of five different porphyrin, meso-tetraphenylporphyrin (TPP), meso-tetra(p-anisyl)porphyrin (TpAP), tetrasodium meso-tetra(p-sulfonatophenyl)porphyrin (TSTpSPP), meso-tetra(m-hydroxyphenyl)porphyrin (TmHPP), and meso-tetra(m-carboxyphenyl)porphyrin (TmCPP) as well as their N-pincer Pd(II)-complexes such as Pd(II)-meso-tetraphenylporphyrin (PdTPP), Pd(II)-meso-tetra(p-anisyl)porphyrin (PdTpAP), Pd(II)-tetrasodium meso-tetra(p-sulfonatophenyl)porphyrin (PdTSTpSPP), Pd(II)-meso-tetra(m-hydroxyphenyl)porphyrin (PdTmHPP), and Pd(II)-meso-tetra(m-carboxyphenyl)porphyrin (PdTmCPP). These porphyrin N-pincer Pd(II)-complexes were studied and found to be effective in the base-free self-coupling reactions of potassium aryltrifluoroborates (PATFBs) in water at ambient conditions. The catalysts and the products (symmetrical biaryls) were characterized using their spectral data. The high yields of the biaryls, the bio-mimicking conditions, good substrate feasibility, evading the use of base, easy preparation and handling of catalysts, and the application of aqueous media, all make this protocol very attractive from a sustainability and cost-effective standpoint.     

Synthesis and structure determination of Co(HNCN)2 and Ni(HNCN)2

Well-crystallized cobalt and nickel hydrogencyanamide, Co(HNCN)₂ and Ni(HNCN)₂, were synthesized from the corresponding ammonia complexes [M(NH₃)₆]²⁺ under aqueous cyanamide conditions. The X-ray and neutron powder data evidence the orthorhombic system and space group Pnnm. The cell parameters for Co(HNCN)₂ are a=6.572(1), b=8.805(2), c=3.267(1) Å, and Z=2; for the isotypic Ni(HNCN)₂, the cell parameters arrive at a=6.457(1), b=8.768(2), c=3.230(1) Å. The octahedral coordinations of the metal ions are marginally squeezed, with interatomic distances of 4×Co-N=2.134(5) Å, 2×Co-N=2.122(9) Å, and 4×Ni-N=2.133(6) Å, 2×Ni-N=2.035(11) Å. The HNCN⁻ units appear as slightly bent (177.5(2)° for Co(HNCN)₂ and 175.7(2)° for Ni(HNCN)₂) and exhibit cyanamide shape character due to triple- and single-bond C-N distances (1.20(2) vs. 1.33(2) Å for Co(HNCN)₂ and 1.15(2) vs. 1.38(2) Å for Ni(HNCN)₂). The infrared vibration data compare well with those of the three existing alkali-metal hydrogencyanamides.     

Stille Cross‐Coupling of a Racemic Planar‐Chiral Ferrocene and Crystallographic Trace Analysis of Catalysis Intermediates and By‐products

A pressure‐controlled procedure for the S_N1 reaction of rac‐1‐[(dimethylamino)methyl]‐2‐(tributylstannyl)ferrocene ( 1 ) to rac‐1‐(phthalimidomethyl)‐2‐(tributylstannyl)ferrocene ( 2 ) was developed. Pd⁰‐Catalyzed Stille coupling of 2 with iodobenzene afforded rac‐1‐phenyl‐2‐(N‐phthalimidomethyl)ferrocene ( 5 ) in 74% yield; after trace enrichment by crystallization of the combined mother liquors, one single crystal of each, 5 , catalysis intermediate trans‐iodo(σ‐phenyl)bis(triphenylarsino)palladium(II) ( 7 ), trans‐diiodobis(triphenylarsino)palladium(II) ( 8 ), and rac‐2,2′‐bis(phthalimidomethyl)‐1,1′‐biferrocene ( 9 ) could be isolated by crystal sorting under a microscope and characterized by X‐ray crystal structure analysis. Furthermore, 5 was deprotected to amine ( 11 ), which does even survive the Birch reduction to rac‐1‐(aminomethyl)‐2‐(cyclohexa‐2,5‐dienyl)ferrocene ( 12 ).     

Standard Molar Enthalpies of Formation of Ce(TCA)_3·3H_2O(s) and Ce(TCA)(C_9H_6NO)_2(s)

IntroductionBothrareearthions1and 8 hydroxyquinolineareofantibacterialfunction ,2 andtheircomplexeshavemorepowerfuldisinfection .Theirbinarycomplexeswerereport edasearlyasin 196 3.Atthesametime ,theresearchontheirternarycomplexeshavebecomeveryactiveinrecentyears,andtheyarewidelyappliedinmanyfields .3 6Dong6 reportedthesynthesisandcharacterizationofthecomplexesofrareearthtrichloroaceticacidsaltswith 8 hy droxyquinoline.Itsapplicationinleathermouldyproofshowedthatthecomplexeshavepowerfuldisinfe…