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.

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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.

     

Das Carotinoidspektrum der Hagebutten von Rosa pomifera: Nachweis von (5Z)-Neurosporin; Synthese von (3R, 15Z)-Rubixanthin

Carotenoids from Hips of Rosa pomifera: Discovery of (5Z)-Neurosporene; Synthesis of (3R, 15Z)-Rubixanthin Extensive chromatographic separations of the mixture of carotenoids from ripe hips of R. pomifera have led to the identification of 43 individual compounds, namely (Scheme 2): (15 Z)-phytoene (1) , (15 Z)-phytofluene (2) , all-(E)-phytofluene (2a) , ξ-carotene (3) , two mono-(Z)-ξ-carotenes ( 3a and 3b ), (6 R)-?, ψ-carotene (4) , a mono-(Z)-?, ψ-carotene (4a) , β, ψ-carotene (5) , a mono-(Z)-β, ψ-carotene (5a) , neurosporene (6) , (5 Z)-neurosporene (6a) , a mono-(Z)-neurosporene (6b) , lycopene (7) , five (Z)-lycopenes (7a–7e) , β, β-carotene (8) , two mono-(Z)-β, β-carotenes (probably (9 Z)-β, β-carotene (8a) and (13 Z)-β, β-carotene (8b) ), β-cryptoxanthin (9) , three (Z)-β-cryptoxanthins (9a–9c) , rubixanthin (10) , (5′ Z)-rubixanthin (=gazaniaxanthin; 10a ), (9′ Z)-rubixanthin (10b) , (13′ Z)- and (13 Z)-rubixanthin (10c and 10d , resp.), (5′ Z, 13′ Z)- or (5′ Z, 13 Z)-rubixanthin (10e) , lutein (11) , zeaxanthin (12) , (13 Z)-zeaxanthin (12b) , a mono-(Z)-zeaxanthin (probably (9 Z)-zeaxanthin (12a) ), (8 R)-mutatoxanthin (13) , (8 S)-mutatoxanthin (14) , neoxanthin (15) , (8′ R)-neochrome (16) , (8′ S)-neochrome (17) , a tetrahydroxycarotenoid (18?) , a tetrahydroxy-epoxy-carotenoid (19?) , and a trihydroxycarotenoid of unknown structure. Rubixanthin (10) and (5′ Z)-rubixanthin (10a) can easily be distinguished by HPLC. separation and CD. spectra at low temperature. The synthesis of (3 R, 15 Z)-rubixanthin (29) is described. The isolation of (5 Z)-neurosporene (6a) supports the hypothesis that the ?-end group arises by enzymatic cyclization of precursors having a (5 Z)- or (5′ Z)-configuration.     

Triterpene glycosides ofHedera helix I. The structures of glycosides L-1, L-2a,L-2b,L-3, L-4a,L-4b,L-6a,L-6b,L-6c,L-7a,and L7-b from the leaves of common ivy

The leaves of common ivy have yielded 11 triterpene glycosides: the 3-O-α-L-pyranosides of oleanolic acid (1), of echinocystic acid (2), and of hederagenin; the 3-O-[O-α-L-rhamnopyranosyl-(1→2)-α-L-arabinopyranoside]s of oleanolic acid (4), of echinocystic acid (5), and of hederagenin (6); the O-α-L-rhamnopyranosyl-(1→4)-O-β-D-glucopyranosyl-(1→6)-O-β-D-glucopyranosyl ester of hederagenin 3-O-α-L-pyranoside (7); the O-β-D-glucopyranosyl-(1→6)-O-β-D-glucopyranosyl ester of hederagenin 3-O-[O-α-L-pyranosyl-(1→2)-α-L-arabinopyranoside] (9); and the O-α-L-rhamnopyranosyl-(1→4)-O-β-D-glucopyranosyl-(1→6)-O-β-D-glucopyranosyl esters of oleanolic acid, echinocystic acid, and hederagenin 3-O-[O-α-L-rhamnopyranosyl-(1→2)-β-D-glucopyranoside]s (8), (10), and (11), respectively. This is the first time that compounds (1), (2), (5), (7), (9), and (10) have been found in this plant. Simferopol' State University. Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 742–746, November–December, 1994.     

Synthesis of Differently Substituted N- and P-Aminodiphosphinoamine PNPN-H Ligands

Abstract

On the basis of the known aminodiphosphinoamine ligand Ph₂PN(i-Pr)P(Ph) N(i-Pr)-H (3a), differently substituted aminodiphosphinoamine PNPN-H ligands (3) were prepared. By using different synthetic methods, the N-substituted ligands Ph₂PN (i-Pr)P(Ph)N(c-Hex)-H (3b), Ph₂PN(c-Hex)P(Ph)N(i-Pr)-H (3g), and Ph₂PN(i-Pr)P(Ph) N[(CH₂)₃Si(OEt)₃]-H (3c), in addition to the formerly described Ph₂PN(n-Hex)P (Ph)N (i-Pr)-H (3h), Ph₂PN(i-Pr)P(Ph)N(Et)-H (3d), Ph₂PN(i-Pr)P(Ph)N(Me)-H (3e), and Ph₂PN(c-Hex)P(Ph)N(c-Hex)-H (3f), were obtained. In addition, Ph₂PN(i-Pr)P(Me)N(i-Pr)-H (3i), (cyclopentyl)₂PN(i-Pr)P(Ph)N(i-Pr)-H (3j), (-O-CH₂-CH₂-O-)PN(i-Pr)P(Ph)N(i-Pr)-H (3k), and (1-Ad)₂PN(i-Pr)P(Ph)N(i-Pr)-H (3l) were prepared with different P-substitutions. All compounds were characterized and the molecular structures of the intermediates Ph₂PN(i-Pr)P(Ph)Cl (1a) and (cyclopentyl)₂PN(i-Pr)P(Ph)Cl (1e) and the ligand (1-Ad)₂PN(i-Pr)P(Ph)N(i-Pr)-H (3l) were investigated by single-crystal X-ray diffraction.

Supplemental materials are available for this article. Go to the publisher's online edition of Phosphorus, Sulfur, and Silicon and the Related Elements to view the free supplemental file.     

Synthesis and structure of FeRu3(CO)13(μ-PPh2)2; A “64-electron” cluster complex with a planar triangulated rhomboidal array of metal atoms

The species FeRu₃(CO)₁₃(μ-PPH₂)₂, synthesized from Ru₃(CO)₁₂ and Fe(CO)₄(Ph₂PPPh₂),has been characterized both spectroscopically and via a single-crystal X-ray structural analysis. This complex crystallizes in the centrosymmetric triclinic space group P$\text{1}$ [No. 2, C_i¹] with a  10.066(3), b  12.899(3), c  17.003(4) Å, α  111.89(2), β  91.02(2), γ  102.00(2)°, V  1992.7(9) ų, Z  2, ?(obsd)  1.79(2) g cm^-3 and ?(calcd)  1.82 cm^-3. Diffraction data were collected with a Syntex P2₁ automated four-circle diffractometer and the structure was refined to R_F  6.0% and R_WF  3.6% for all 5213 reflections (R_F  3.8%, R_WF  3.6% for those 4140 reflections with |F_o|> 3σ(|F_o|).The metal atoms define a planar triangulated rhombus, with atoms Ru(1) and Ru(2) at the bridgehead, and Fe(1) and Ru(3) at the acute apices. Fe(1) is linked to four terminal carbonyl ligands and is associated with the heteronuclear bonds Fe(1)Ru(1)  2.861(1) Å and Fe(1)Ru(2)  2.868(1) Å. The ruthenium atoms are each bonded to three terminal carbonyl groups. The retheniumruthenium distances are Ru(1)Ru(2)  3.098(1), Ru(1)Ru(3)  3.147(1), and Ru(2)Ru(3)  3.171(1) Å. The structure is completed by Ph₂P bridges across the Ru(1)Ru(3) and Ru(2)(ru(3) vectors (<Ru(1)P(1)Ru(3)  84.89(5)° and <Ru(2)P(2)Ru(3)  85.56(6)°).     

Metal derivatives of thiosemicarbazones: crystal structure of [chloro bis(triphenylphosphino) (thiophene-2-carbaldehyde thiosemicarbazone) copper(I)] complex

Reactions of copper(I) halides (X = Cl, Br, I) with thiophene-2-carbaldehyde thiosemicarbazone and triphenylphosphine in 1 : 1 : 2 molar ratio yield tetrahedral mononuclear complexes, [CuX(η¹-S-Httsc)(Ph₃P)₂] (X = Cl, 1; Br, 2; I, 3), characterized by elemental analysis, IR, NMR (¹H, ¹³C, ³¹P), and single crystal X-ray crystallography (1). The unit cell of 1 has two independent distorted tetrahedral molecules (1a and 1b) with different bond parameters. One acetonitrile is entrapped between them. Crystal data: C₈₆H₇₇Cl₂Cu₂N₇P₄S₄ 1: triclinic, P-1, a = 12.8810(9), b = 18.5049(13), c = 18.7430(13) Å, α = 63.7130(10), β = 89.0960(10), γ = 85.5010(10)°, V = 3992.4(5) ų, Z = 2, R _(int) = 0.0314. Bond parameters: 1a, Cu(1A)–Cl(1A), 2.3803(5); Cu(1A)–S(1A), 2.3822(5); Cu(1A)–P(1A), 2.2498(5) Å; P(1A)–Cu(1A)–P(2A), 124.294(19)°; 1b, Cu(1B)–Cl(1B), 2.3975(5); Cu(1B)–S(1B), 2.3756(5); Cu(1B)–P(1B), 2.2777(5) Å; P(1B)–Cu(1B)–P(2B), 127.156(19)°.     

Bis(tetraphenylantimony) succinate,malate, and tartrate: Syntheses and structures

The reactions of pentaphenylantimony with succinic, malic, and tartaric acids (mole ratio 2: 1) in toluene afford bis(tetraphenylantimony) succinate (I), malate (II), and tartrate (III) in yields of 98, 92, and 94%, respectively. According to the X_ray diffraction analysis results, molecules I and II are centrosymmetric. In compound II, the hydroxy group in the acid residue is disordered over two positions. Crystal III includes two types of crystallographically independent molecules (a and b). The antimony atoms in compounds I, II, IIIa, and IIIb have distorted trigonal bipyramidal coordination modes. The axial angles C_axSbO_ax are 166.80(8)° (I); 174.8(2)° (II); 176.4(4)°, 177.4(3)° (IIIa); and 173.3(4)°, 172.7(4)° (IIIb). The equatorial angles C_eqSbC_eq vary in the ranges 99.3(1)°–154.5(1)° (I); 115.2(2)°–123.3(2)° (II); 115.7(4)°–123.3(4)° 115.2(5)°–125.6(5)° (IIIa); and 107.9(4)°-129.1(4)°, 113.7(4)°-124.8(5)° (IIIb). The Sb-C and Sb-O bonds are 2.138(3)-2.176(3), 2.319(2) Å (I); 2.111(6)–2.163(5), 2.243(4) Å (II); 2.072(13)–2.169(11), 2.252(7), 2.284(7) Å (IIIa); and 2.047(11)–2.190(11), 2.224(7), 2.256(7) Å (IIIb). The intramolecular distances Sb…O=C are 2.528(3) (I); 3.267(7) (II); 3.381(7), 3.436(7) (IIIa); and 3.351(7), 3.162(7) Å (IIIb). For structures I, II, and III, the CIF files are CCDC 929151, 941542, and 941543, respectively.     

The Active Mixed Anhydrides of Phosphorous Ph-Acids

Abstract

The ³¹P spectra of H₃PO₃ + Ac₂O and PCl₃ + Ac₂O contain signals which were assigned to the following compounds (δ_p, J_pH): H₃PO₃(8,5; 702), AcO(OH)P(O)H (2,2; 739), (AcO)₂P(O)H (-2,7; 763), (AcO)₃P (131,6); PCl₃ (220,7), AcOPCl₂ (194,6), (AcO)₂PCl (167,O), (AcOl₃P (131,5). The active intermediates with -PH(O)Cl groups are formed on treating phosphorous PH-acids with AcCl, and in other reactions¹. These intermediates are added to aldehydes and ketones resulting in compounds (I), (11) and (111). The compounds of type (11) treated with AcOH transform into compounds of different structure, e.g. into (IV) and (V).     

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.     

Polarographie in 1,2-Propandiolcarbonat, 3. Mitt.: Verbindungen von Titan,Vanadin und Chrom

Zusammenfassung Titan(III)chlorid, Titan (IV)oxyperchlorat, Vanadin(III)chlorid, Vanadin(IV)oxyperchlorat, Chrom(III)chlorid und Chrom(III)perchlorat wurden in 1,2-Propandiolcarbonat polarographisch untersucht; die Art der Grenzströme, die Diffusionsstromkonstanten, die Diffusionskoeffizienten, die Art der Abscheidungsvorgänge und die Lage der Halbwellenpotentiale, bez. auf die gesätt. wäßr. Kalomelelektrode, wurden bei 25° in 0,1M-Lösungen von Tetraäthylammoniumperchlorat bestimmt. Es wurden die Reduktionsvorgänge Ti(IV)–Ti(III), V(III)–V(II), V(IV)–V(II), Cr(III)–Cr(II) und Cr(II)–Cr(0) aufgefunden, wobei nur V(III)–V(II) reversibel verläuft.

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Polarographic investigation have been carried out on titanium(III)chloride, titanium(IV)oxoperchlorate, vanadium(III)chloride, vanadium(IV)oxoperchlorate, chromium(III)chloride and chromium(III)perchlorate in 1,2-propanediol-carbonate; the nature of the limiting currents, the diffusion current constants, the diffusion coefficients, the reversibility or irreversibility of the electrode process and the half-wave potentials vs. aqueous saturated calomel electrode have been determined in 0,1M solutions of tetraethylammonium perchlorate at 25°. Reduction waves were found corresponding to Ti(IV)–Ti(III), V(III)–V(II), V(IV)–V(II), Cr(III)–Cr(II) and Cr(II)–Cr(0)

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Mit 2 Abbildungen

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1. Mitt.:V. Gutmann, M. Kogelnig undM. Michlmayr, Mh. Chem.99, 693 (1968).

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2. Mitt.:V. Gutmann, M. Kogelnig undM. Michlmayr, Mh. Chem.99, 699 (1968).     

Thiolate-bridged heterometallic complexes of manganese and platinum: Synthesis and molecular structures of (CO)4Mn(μ-SPh)Pt(PPh3)2, (CO)3(PPh3)Mn(μ-SPh)Pt(PPh3)(CO), and (CO)3Mn(μ-SPh)Pt(PPh3)(Dppm)

A reaction of the dimer [Mn(CO)₄(SPh)]₂ with (PPh₃)₂Pt(C₂Ph₂) gave the heterometallic complex (CO)₄Mn(μ-SPh)Pt(PPh₃)₂ (I) and its isomer (CO)₃(PPh₃)Mn(μ-SPh)Pt(PPh₃)(CO) (II). A reaction of complex I with a diphosphine ligand (Dppm) yielded the heterometallic complex (CO)₃Mn(μ-SPh)Pt(PPh₃)(Dppm) (III). Complexes I–III were characterized by X-ray diffraction. In complex I, the single Mn-Pt bond (2.6946(3) ?) is supplemented with a thiolate bridge with the shortened Pt-S and Mn-S bonds (2.3129(5) and 2.2900(6) ?, respectively). Unlike complex I, in complex II, one phosphine group at the Pt atom is exchanged for one CO group at the Mn atom. The Mn-Pt bond (2.633(1) ?) and the thiolate bridge (Pt-S, 2.332(2) ?; Mn-S, 2.291(2) ?) are retained. In complex III, the Mn-Pt bond (2.623(1) ?) is supplemented with thiolate (Pt-S, 2.341(2) ?; Mn-S, 2.292(2) 0?) and Dppm bridges (Pt-P, 2.240(1)?; Mn-P, 2.245(2) ?). Apparently, the Pt atom in complexes I–III is attached to the formally double bond , as in Pt complexes with olefins.     

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)     

CrIII-Phthalocyaninate: Darstellung und spektroskopische Eigenschaften von Di(halogeno)phthalocyaninatochromaten(III)

Cr^III Phthalocyaninates: Synthesis and Spectroscopical Properties of Di(halo)phthalocyaninato(2 –)chromates(III) [Cr(H₂O)₂Pc^2?]⁺ reacts in acetone with (ⁿBu₄N)X to yield less soluble tetra(n-butyl)ammonium di(halo)phthalocyaninato(2 –)chromate(III), (ⁿBu₄N)[Cr(X)₂Pc^2?] (X = F, Cl, Br, I). In the differential pulse voltammograms the first ring oxidation is observed at 0,80 V, the ring reduction at ?1,48 V and the metal reduction (Cr(III)/Cr(II)) at ?0,80 V (averaged potentials). The last is followed by a partial dissociation of one of the halo ligands. In the UV-VIS-NIR spectra there are three weakly absorbing spin-allowed trip-quarter(TQ) transitions (TQ1 (8,4) < TQ2 (11,5) < TQ3 (20,6); averaged values (av) in 10³ cm^?1), a (Pc + X)-CrCT transition (31,3; av in 10³ cm^?1) and the characteristic π-π* transitions of the Pc^2? ligand (B (14,5) < Q₁ (24,5) < Q₂ (29,2) < N (36,0) < L (41,0); av in 10³ cm^?1). Q₁ and (Pc + X)-CrCT depend strongly on the halo ligands. Prominent luminescence spectra are obtained by excitation within the TQ1 region, in which the spin-forbidden trip-sextet transition (8330 (X = F), 7680 (Cl), 7460 (Br) 7450 cm^?1 (I)) dominates at low temperatures (T < 50 K). The vibrational spectra are discussed. In coincidence of the excitation lines with TQ3, v_s(Cr? X) at 458 (X = F) < 246 (Cl) < 157 (Br) < 107 cm^?1 ( I ) is selectively resonance Raman enhanced. v_as(Cr? X) is observed in the FIR spectrum at 522 (X = F) < 283/326 (Cl) < 227 (Br) < 205 cm^?1 ( I ).     

Equilibrium studies on some heteroligand hydroxo complexes of lanthanons with iminodiacetic acid and citraconic or maleic acid

Mixed-ligand ternary complexes of La(III), Pr(III), Nd(III), Gd(III), and Dy(III) with iminodiacetic acid (IMDA) and citraconic (CCA) or maleic acid (MIA), have been studiedpH-metrically. Their formation takes place through the stepwise addition of the secondary ligand (IMDA) to the initially formed 1:1, Ln(III)—CCA/MIA binary species. The resulting ternary complexes undergo hydrolysis to form their hydroxo derivatives simultaneously. The stability constants of the hydroxo species are calculated for constant temperature (27 ± 1°C) and ionic strength (I=0.1M KNO₃). The relative order of stability is: La(III)

Gleichgewichtsuntersuchungen an einigen Heteroliganden-Hydroxo-Komplexen von Lanthanid-Ionen mit Iminodiessigsäure und Citracon- oder Maleinsäure

Zusammenfassung Es wurden ternäre Komplexe von La(III), Pr(III), Nd(III), Gd(III) und Dy(III) mit gemischten Liganden [Iminodiessigsäure (IMDA) und Citraconsäure (CCA) oder Maleinsäure (MIA)] mittelspH-metrischer Methoden untersucht. Diese Komplexe werden über die stufenweise Addition des Sekundärliganden (IMDA) zu den primär gebildeten 1:1 Ln(III)—CCA/MIA Spezies gebildet. Zugleich erleiden die resultierenden ternären Komplexe Hydrolyse und gehen in die entsprechenden Hydroxo-Komplexe über. Die Stabilitätskonstanten der Hydroxo-Komplexe wurden für konstante Temperatur (27 ± 1°C) und Ionenstärke (I=0.1M KNO₃) berechnet. Die relative Reihung bezüglich der Stabilitäten ergab sich folgendermaßen: La(III)     

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.     

From 1D to 2D Cd(II) and Zn(II) Coordination Networks by Replacing Monocarboxylate with Dicarboxylates in Partnership with Azine Ligands: Synthesis,Crystal Structures,Inclusion, and Emission Properties

Eight mixed-ligand coordination networks, [Cd(2-aba)(NO₃)(4-bphz)_3/2]_n·n(dmf) (1), [Cd(2-aba)₂(4-bphz)]_n·0.75n(dmf) (2), [Cd(seb)(4-bphz)]_n·n(H₂O) (3), [Cd(seb)(4-bpmhz)]_n·n(H₂O) (4), [Cd(hpa)(3-bphz)]_n (5), [Zn(1,3-bdc)(3-bpmhz)]_n·n(MeOH) (6), [Cd(1,3-bdc)(3-bpmhz)]_n ·0.5n(H₂O)·0.5n(EtOH) (7), and [Cd(NO₃)₂(3-bphz)(bpe)]_n·n(3-bphz) (8) were obtained by interplay of cadmium nitrate tetrahydrate or zinc nitrate hexahydrate with 2-aminobenzenecarboxylic acid (H(2-aba)), three dicarboxylic acids, sebacic (decanedioic acid, H₂seb), homophthalic (2-(carboxymethyl)benzoic acid, H₂hpa), isophthalic (1,3-benzenedicarboxylic acid, H₂(1,3-bdc)) acids, bis(4-pyridyl)ethane (bpe) and with four azine ligands, 1,2-bis(pyridin-4-ylmethylene)hydrazine (4-bphz), 1,2-bis(1-(pyridin-4-yl)ethylidene) hydrazine (4-bpmhz), 1,2-bis(pyridin-3-ylmethylene)hydrazine (3-bphz), and 1,2-bis(1-(pyridin-3-yl) ethylidene)hydrazine (3-bpmhz). Compounds 1 and 2 are 1D coordination polymers, while compounds 3–8 are 2D coordination polymers. All compounds were characterized by spectroscopic and X-ray diffraction methods of analysis. The solvent uptakes and stabilities to the guest evacuation were studied and compared for 1D and 2D coordination networks. The de-solvated forms revealed a significant increase of emission in comparison with the as-synthesized crystals.     

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.     

Fluorinated tris(pyrazolyl)borates. Syntheses and characterization of sodium and copper complexes of [HB(3-(CF3),5-(Ph)Pz)3]−

Sodium salt of the fluorinated tris(pyrazolyl)borate ligand [HB(3-(CF₃),5-(Ph)Pz)₃]⁻ has been synthesized from the corresponding pyrazole and NaBH₄ in high yield. It forms stable adducts with oxygen-based donors like THF and water. [HB(3-(CF₃),5-(Ph)Pz)₃]Na(THF) is monomeric in the solid state whereas {[HB(3-(CF₃),5-(Ph)Pz)₃]Na(H₂O)}_n forms a polymeric chain structure. These tris(pyrazolyl)boratosodium adducts show intra and/or inter-molecular sodium–fluorine interactions. X-ray crystal structures of [HB(3,5-(CF₃)₂Pz)₃]Na(OEt₂) and {[HB(3-(CF₃),5-(CH₃)Pz)₃]Na(H₂O)}₂ also display similar CF⋯Na contacts. The copper carbon monoxide complex [HB(3-(CF₃),5-(Ph)Pz)₃]CuCO was prepared by treating [HB(3-(CF₃),5-(Ph)Pz)₃]Na(THF) with CuOTf in the presence of CO. The infra-red stretching frequency data show relatively high ν_CO value (2103 cm⁻¹) indicating the presence of highly electrophilic copper site on [HB(3-(CF₃),5-(Ph)Pz)₃]CuCO. Crystal structure of 3-(CF₃),5-(Ph)PzH is also reported. It forms “tub” shaped tetramers in the solid state.     

Tannins and Related Compounds from Quisqualis Indica

Continuous exploration of the chemical constituents of Combretaceous plants has led to the discovery of two novel ellagitannins, quisqualin A ( 1 ) and quisqualin B ( 2 ), from the fruits of Quisqualis indica. A total of twenty-one other tannins were also isolated from either the fruits or leaves of Q. indica. including [I] eleven ellagitannins: 2,3-(S)-HHDP-D-glucose ( 3 ), 2,3-(S)-HHDP-4-O-galloyl-D-glucose ( 4 ), 2,3-(S)-HHDP-6-O-galloyl-D-glucose ( 5 ), 2,3-(S)-HHDPA6-di-O-galloyl-D-glucose ( 6 ). pedunculagin ( 7 ), punicalagin ( 8 ), eugeniin ( 9 ), 1-desgalloyleugeniin ( 10 ), casuariin ( 11 ), 5-desgalloylstachyurin ( 12 ), castalagin ( 13 ); [II] five gallotannins-. 6-O-galloyl-D-glucose ( 14 ), 1,6-di-O-galloyl-β-D-glucose ( 15 ), 2,3-di-O-galloyl-D-glucose ( 16 ), 3,4-di-O-galloyl-D-glucose ( 17 ), 4,6-di-O-galloyl-D-glucose ( 18 ); [III] four phenol-carboxylic acids: gallic acid ( 19 ), ellagic acid ( 20 ), flavogallonic acid ( 21 ), brevifolin carboxylic acid ( 22 ) and [IV] one other hydrolyzable tannin: punicalin ( 23 ).     

New examples of mixed-ligand bis(hexafluoroacetylacenonato)copper(II) complexes with 3-imidazoline nitroxide radicals at a Cu(C5HF6O2)2∶L=3∶2 ratio (L2=C14H19N2O,L3=C13H17N2O3)

The crystal structures of two (hexafluoroacetylacetonato)copper(II) complexes with 3-imidazoline nitroxide radicals, [Cu(C₅HF₆O₂)₂]₃ (C₁₄H₁₉N₂O)₂ (I) and [Cu(C₅HF₆O₂)₂]₃ (C₁₃H₁₇N₂O₃)₂ (II), have been determined. The compounds are triclinic (PI, Z=1) with a=8.730(2), b=10.357(2), c=21.996(5) Å, α=103.24(2), β=94.03(2), γ=95.04(2)⁰, V=1920(1) ų for I and a=8.679(2), b=14.769(4), c=15.368(4) Å, α=85.58(2), β=96.25(1), γ=104.60(1)⁰, V=1893(1) ų for II. Complexes I and II are molecular. The trinuclear molecules are centrosymmetric relative to the Cu(1) atom. The coordination polyhedron of Cu(1) is a square bipyramid formed by the O atoms of the hfac anions and nitroxide radicals (average Cu?O_hfac 1.92(1) for I and 1.93(1) Å for II; Cu?O_N?O 2.47(1) for I and 2.56(1) Å for II). The coordination polyhedron of Cu(2) is a trigonal bipyramid formed by the O atoms of the hfac anions (Cu?O_hfac 1.91(1)–2.12(1) for I and 1.91(1)–2.09(1) Å for II) and an imine N atom of the radical (Cu(2)?N(2) 2.00(1) for I and 2.03(1) Å for II). The molecules are linked by van der Waals forces.