Zdirad Žák - Academia.edu (original) (raw)
Papers by Zdirad Žák
Transition Metal Chemistry, Apr 1, 2004
Polish Journal of Chemistry, 2002
The complex compounds of the formula (R)[Ni I I I (tdt) 2 ], R = Met 4 N (I), Et 4 N (II), Pr 4 N... more The complex compounds of the formula (R)[Ni I I I (tdt) 2 ], R = Met 4 N (I), Et 4 N (II), Pr 4 N (III), MePh 3 P (IV), Ph 4 P (V); tdt = l-toluene-3,4-dithiole have been synthesized. The crystal structures of the compounds III and IVwere determined by X-rays studies. Bond valence as a function of inter-nuclear distance for Ni-S bonds was estimated. On the basis of physico-chemical measurements and bond-valence sum model, the formal oxidation state III of Ni atoms for both structures was proposed.
Zeitschrift f�r anorganische und allgemeine Chemie, 1996
Inorganica Chimica Acta, Mar 1, 2003
The sodium salt of the double Keggin anion [Fe4C~2W18070H6] Io-has been prepared from Na2W0,.2H20... more The sodium salt of the double Keggin anion [Fe4C~2W18070H6] Io-has been prepared from Na2W0,.2H20, Fe(N03),.9H20, and C U (C H~C O O)~. H~O in water and isolated in cystalline form as NaloFe4Cu2W18070H6~29H20: monoclinic, P2,/n, a = 13.079 (3) A, b = 17.772 (4) A, c = 21.104 (7) A, p = 93.46 (2)O, V = 4896 (2) A', 2 = 2, D(ca1cd) = 3.75 g cmW3. This is the first polytungstate ion to contain six paramagnetic centers and the first with four paramagnetic centers bridged by a single oxygen atom. The anion contains two octahedral Cu(I1) sites, two octahedral Fe(II1) sites, and two tetrahedral Fe(II1) sites forming a Cu2Fe402, core. The cationic portion of the structure consists of two [Na502,15+ oxygen-bridged structures draping the anion in necklace fashion. The magnetic susceptibility of the salt was determined for the temperature range 4-374 K; it exhibits strong antiferromagnetic interaction at low temperature. xMTshows a pronounced decrease at about 100 K and approaches a constant value at 20 K. The EPR spectrum in the 77-300 K range consists of a broad feature (1000 G) with little structure centered at about g = 2.2 and a weaker second line at about g = 4.4. The broad line suggests that the six central metal ions participate in the magnetism in this temperature range. (1) (a) Delaware State College.
Journal of Materials Chemistry, 2006
Four new cyano-bridged [MnIIMIIIMnII] heterotrinuclear complexes (MIII = Cr, Fe, Co) have been sy... more Four new cyano-bridged [MnIIMIIIMnII] heterotrinuclear complexes (MIII = Cr, Fe, Co) have been synthesized and crystallographically characterized: {[(H2O)L1Mn–NC–Cr(CN)4–CN–MnL1(H2O)]}3[Cr(CN)6]·10H2O 1, [(H2O)L2Mn–NC–M(CN)4–CN–MnL2(NCS)]·2H2O 2, [(H2O)L2Mn–NC–Fe(CN)4–CN–MnL2(H2O)](NCS)·1.5H2O 3, and [(H2O)L2Mn–NC–Co(CN)4–CN–MnL2(H2O)](NCS)·1.5H2O 4 (L1 = 2,13-dimethyl-3,6,9,12,18-pentaazabicyclo[12.3.1]octadeca-1(18),2,12,14,16-pentaene, L2 = 2,13-dimethyl-6,9-dioxa-3,12,18-triazabicyclo[12.3.1]octadeca-1(18),2,12,14,16-pentaene). The crystal structure of 1 consists of independent [MnCrMn] monocations whose charges are counterbalanced by [Cr(CN)6]3− anions. The crystal structure of 2 consists of neutral heterotrinuclear [MnCrMn] species, with the isothiocyanato ion coordinated to one of the manganese atoms. Compounds 3 and 4 are isomorphous. Their crystal structure consists of centrosymmetric [MnMMn] entities, uncoordinated NCS− ions, and solvent molecules. The magnetic properties of the four complexes have been investigated. Compounds 1 and 2 are new examples of systems with an irregular spin state structure, exhibiting the characteristic minimum on the the χMTversusT curves. The exchange interaction between the chromium(III) and the manganese(II) ions is antiferromagnetic (1: J = −9.8 cm−1; 2: J = −6.52 cm−1). For compound 3, the exchange interaction between manganese(II) and iron(III) was found to be ferromagnetic.
Zeitschrift Fur Kristallographie, 1997
Acta Crystallographica Section C-crystal Structure Communications, Apr 15, 1991
= 0.0416 for 1071 observed reflections with Fo >-3"0tr(Fo). Compound (II): bis(1,2,3,4-tetrahydro... more = 0.0416 for 1071 observed reflections with Fo >-3"0tr(Fo). Compound (II): bis(1,2,3,4-tetrahydro-2,4-dioxo-5-pyrimidinecarboxylato)manganese(II) dihydrate, [Mn(CsH3N204)2].2H20, Mr = 401.15, monoclinic, P21/n, a=5.0615(9), b= 10.118(1), c=13.812(2)A, /3=95.
Revue Roumaine De Chimie, 2002
A new heteropolymetallic system, [Ni 2 (fsal-33)(H 2 O) 4 ][Cr(bipy)(C 2 O 4 ) 2 ] 2 H 2 O, 1, wa... more A new heteropolymetallic system, [Ni 2 (fsal-33)(H 2 O) 4 ][Cr(bipy)(C 2 O 4 ) 2 ] 2 H 2 O, 1, was obtained by reacting K[Cr(bipy)(C 2 O 4 ) 2 ] with [Ni 2 (fsal-33)Cl 2 ] 2H 2 O (H 2 fsal-33 is the symmetric macrocyclic binucleating Schiff-base ligand obtained by condensation of 2,6-diformyl-4-methylphenol with 1,3-propanediamine). The crystal structure of compound 1 was solved: it crystallizes in the monoclinic system, space group P2 1 /c (no. 14), a = 10.356(1) A, b = 13.599(1) A, c = 18.983(1) A, β = 99.08(1)°. The crystallographic investigation reveals a complex three-dimensional structure based on hydrogen-bond interactions between the aqua ligands coordinated to the nickel atoms and the oxalato groups arising from the [Cr(bipy)(C 2 O 4 ) 2 ] - anions. The π-π stacking interactions (∼3.4 A) between the 2,2-bipyridine ligands coordinated to the chromium(III) ions play an important role in sustaining the supramolecular solid-state architecture. The value of the Χ M T product at T 289 K (6.5 cm 3 mol - 1 K) corresponds to the expected value for four uncorrelated local spins. The electronic spectrum of 1 displays the characteristic features of both hexacoordinated Ni(II) and Cr(III) ions.
Journal of The Chemical Society-dalton Transactions, 1995
ABSTRACT
Polish Journal of Chemistry, 1999
Acta crystallographica, 1978
LiSO3F is, monoclinic, space group C2/m, Z = 4, with a = 8.54 (2), b = 7.62 (I), c = 4.98 (2) A, ... more LiSO3F is, monoclinic, space group C2/m, Z = 4, with a = 8.54 (2), b = 7.62 (I), c = 4.98 (2) A, fl= 90-0 (3)°; D,,, = 2.20, D C = 2.17 g cm-3. The structure, which was refined to R-0.085 for 332 densitometer intensities, consists of Li + and SO3Fions arranged in alternating cationic and anionic layers. The layers are bound into a three-dimensional structure by Li-O bonds. The SO3F group is tetrahedral with a fixed position for the F atom. The whole group is coordinated by eight Li atoms in a slightly distorted cubic arrangement. Li atoms are coordinated tetrahedrally by four O atoms. Two LiO 4 tetrahedra share a common edge to form Li206 groups. The important bond lengths are SO 1.455 and 1.424, S-F 1.555, and Li-O 2-045 and 1.903 A. The e.s.d.'s are 0.004-0.03 A for the lengths and 0.2-0.9 ° for the angles.
Chemischer Informationsdienst, Sep 21, 1971
Acta Crystallographica Section A, Aug 8, 1996
Alar<>e number of new compounds have been synthesised and structurally ch;•acte1ized in the A-MoP... more Alar<>e number of new compounds have been synthesised and structurally ch;•acte1ized in the A-MoP -0 system where A is an alkali or alkaline-earth metal and Mo is in the oxidation states below VI. In contrast to the rich stmctural chemistry of molybdenum phosphates, little is known about their arsenate analogues. As a part of our research program to study the str1.1ctural chemistry of transistion-metal arsenates, we began to synthesise new compounds in the A-MoV1-AsY-O system usin~ hydrothenmu techniques. By incorporating either organic or hydrated morgarric cations in the hydrothennal reactions, novel frameworks have been produced. In tins presentation, t11e synthesis and crystal structures of three se1ies of molybdenum(VI) arsenates will be given. They include: (1) A 2 Mo20 5 (HAs0 4)2•H20 (A = Cs and CsHsNH); (2) As[Mo~<?l2 (OH)hAs0 4 •2H 2 0 (A = Rb and Cs), and the tl1ermal decompos1t:J.on product Cs7(Mo03)02As04: and (3) SrMo03(HAs04)•H20 and Ba(Mo0 3) 6 (As0 4)4(H 2 0h. Structural relationship an1ong some oftl1ese molybdenum arsenates is also discussed.
Chemischer Informationsdienst, Jan 16, 1979
Acta Crystallographica Section C-crystal Structure Communications, Jan 15, 1993
ABSTRACT
Zeitschrift für anorganische und allgemeine Chemie, Nov 1, 1994
Neue O,O′,O″,O‴-Tetratolyl- und Diphenylditolyl-ester der μ-Imido-diphosphorsaure und ihres Monot... more Neue O,O′,O″,O‴-Tetratolyl- und Diphenylditolyl-ester der μ-Imido-diphosphorsaure und ihres Monothio- und Dithioderivates wurden synthetisiert, in ihren Eigenschaften mit den bekannten Phenylestern verglichen und 1H-, 13C- und 31P-NMR-spektroskopisch untersucht. Die Kristall- und Molekulstrukturen des O,O′,O″,O‴-Tetrakis-(2-methyl-phenyl)-μ-imido-diphosphats, 1b, sowie der entsprechenden ortho-, meta-, und para-Tolylester der μ-Imido-monothiodiphosphorsaure (2b, 2c, 2d) konnten gelost werden. Alle Verbindungen bilden uber NH…O-Wasserstoffbrucken Dimere, die auch in unpolaren Losungsmitteln erhalten bleiben. Die Bindungsabstande um die P-Atome nehmen mit sinkender Elektronegativitat der Substituenten zu. Durch 13C{1H, 31P}- Tripelresonanzexperimente wurde das Vorzeichen der 2JPNP- Kopplungskonstanten fur einige Verbindungen bestimmt. Bei Substitution von Phosphoryl- durch Thiophosphorylgruppen werden diese Konstanten negativer. Tetraarylesters of μ-Imido-Diphosphoric Acid and its Thio Derivatives — Structure Investigations New O,O′,O″,O‴-tetratolyl- and ditolyl-diphenylesters of the μ-imido-diphosphoric acid and its mono and dithio derivatives were synthesized, compared with the corresponding tetraphenylesters and investigated by 1H, 13C, and 31P NMR spectroscopy and X-ray crystal structure analysis. Structures of the O,O′,O″,O‴-tetrakis-(2-methyl-phenyl)-μ-imidodiphosphate, 1b, as well as of the corresponding ortho-, meta- and para-tolylesters of the μ-imido-monothiodiphosphoric acid (2a, 2b, 2c) were determined. All the compounds form dimers via NH…O hydrogen bonds in the crystal as well as in nonpolar solvents. The distances around the phosphorus atoms rise with decreasing electronegativity of the phosphorus substituents. Signs of the 2JPNP coupling constants were determined by 13C{1H, 31P} triple resonance experiments for some compounds. These constants become more negative owing to substitution of a phosphoryl by a thiophosphoryl group.
Transition Metal Chemistry, Apr 1, 2004
Polish Journal of Chemistry, 2002
The complex compounds of the formula (R)[Ni I I I (tdt) 2 ], R = Met 4 N (I), Et 4 N (II), Pr 4 N... more The complex compounds of the formula (R)[Ni I I I (tdt) 2 ], R = Met 4 N (I), Et 4 N (II), Pr 4 N (III), MePh 3 P (IV), Ph 4 P (V); tdt = l-toluene-3,4-dithiole have been synthesized. The crystal structures of the compounds III and IVwere determined by X-rays studies. Bond valence as a function of inter-nuclear distance for Ni-S bonds was estimated. On the basis of physico-chemical measurements and bond-valence sum model, the formal oxidation state III of Ni atoms for both structures was proposed.
Zeitschrift f�r anorganische und allgemeine Chemie, 1996
Inorganica Chimica Acta, Mar 1, 2003
The sodium salt of the double Keggin anion [Fe4C~2W18070H6] Io-has been prepared from Na2W0,.2H20... more The sodium salt of the double Keggin anion [Fe4C~2W18070H6] Io-has been prepared from Na2W0,.2H20, Fe(N03),.9H20, and C U (C H~C O O)~. H~O in water and isolated in cystalline form as NaloFe4Cu2W18070H6~29H20: monoclinic, P2,/n, a = 13.079 (3) A, b = 17.772 (4) A, c = 21.104 (7) A, p = 93.46 (2)O, V = 4896 (2) A', 2 = 2, D(ca1cd) = 3.75 g cmW3. This is the first polytungstate ion to contain six paramagnetic centers and the first with four paramagnetic centers bridged by a single oxygen atom. The anion contains two octahedral Cu(I1) sites, two octahedral Fe(II1) sites, and two tetrahedral Fe(II1) sites forming a Cu2Fe402, core. The cationic portion of the structure consists of two [Na502,15+ oxygen-bridged structures draping the anion in necklace fashion. The magnetic susceptibility of the salt was determined for the temperature range 4-374 K; it exhibits strong antiferromagnetic interaction at low temperature. xMTshows a pronounced decrease at about 100 K and approaches a constant value at 20 K. The EPR spectrum in the 77-300 K range consists of a broad feature (1000 G) with little structure centered at about g = 2.2 and a weaker second line at about g = 4.4. The broad line suggests that the six central metal ions participate in the magnetism in this temperature range. (1) (a) Delaware State College.
Journal of Materials Chemistry, 2006
Four new cyano-bridged [MnIIMIIIMnII] heterotrinuclear complexes (MIII = Cr, Fe, Co) have been sy... more Four new cyano-bridged [MnIIMIIIMnII] heterotrinuclear complexes (MIII = Cr, Fe, Co) have been synthesized and crystallographically characterized: {[(H2O)L1Mn–NC–Cr(CN)4–CN–MnL1(H2O)]}3[Cr(CN)6]·10H2O 1, [(H2O)L2Mn–NC–M(CN)4–CN–MnL2(NCS)]·2H2O 2, [(H2O)L2Mn–NC–Fe(CN)4–CN–MnL2(H2O)](NCS)·1.5H2O 3, and [(H2O)L2Mn–NC–Co(CN)4–CN–MnL2(H2O)](NCS)·1.5H2O 4 (L1 = 2,13-dimethyl-3,6,9,12,18-pentaazabicyclo[12.3.1]octadeca-1(18),2,12,14,16-pentaene, L2 = 2,13-dimethyl-6,9-dioxa-3,12,18-triazabicyclo[12.3.1]octadeca-1(18),2,12,14,16-pentaene). The crystal structure of 1 consists of independent [MnCrMn] monocations whose charges are counterbalanced by [Cr(CN)6]3− anions. The crystal structure of 2 consists of neutral heterotrinuclear [MnCrMn] species, with the isothiocyanato ion coordinated to one of the manganese atoms. Compounds 3 and 4 are isomorphous. Their crystal structure consists of centrosymmetric [MnMMn] entities, uncoordinated NCS− ions, and solvent molecules. The magnetic properties of the four complexes have been investigated. Compounds 1 and 2 are new examples of systems with an irregular spin state structure, exhibiting the characteristic minimum on the the χMTversusT curves. The exchange interaction between the chromium(III) and the manganese(II) ions is antiferromagnetic (1: J = −9.8 cm−1; 2: J = −6.52 cm−1). For compound 3, the exchange interaction between manganese(II) and iron(III) was found to be ferromagnetic.
Zeitschrift Fur Kristallographie, 1997
Acta Crystallographica Section C-crystal Structure Communications, Apr 15, 1991
= 0.0416 for 1071 observed reflections with Fo >-3"0tr(Fo). Compound (II): bis(1,2,3,4-tetrahydro... more = 0.0416 for 1071 observed reflections with Fo >-3"0tr(Fo). Compound (II): bis(1,2,3,4-tetrahydro-2,4-dioxo-5-pyrimidinecarboxylato)manganese(II) dihydrate, [Mn(CsH3N204)2].2H20, Mr = 401.15, monoclinic, P21/n, a=5.0615(9), b= 10.118(1), c=13.812(2)A, /3=95.
Revue Roumaine De Chimie, 2002
A new heteropolymetallic system, [Ni 2 (fsal-33)(H 2 O) 4 ][Cr(bipy)(C 2 O 4 ) 2 ] 2 H 2 O, 1, wa... more A new heteropolymetallic system, [Ni 2 (fsal-33)(H 2 O) 4 ][Cr(bipy)(C 2 O 4 ) 2 ] 2 H 2 O, 1, was obtained by reacting K[Cr(bipy)(C 2 O 4 ) 2 ] with [Ni 2 (fsal-33)Cl 2 ] 2H 2 O (H 2 fsal-33 is the symmetric macrocyclic binucleating Schiff-base ligand obtained by condensation of 2,6-diformyl-4-methylphenol with 1,3-propanediamine). The crystal structure of compound 1 was solved: it crystallizes in the monoclinic system, space group P2 1 /c (no. 14), a = 10.356(1) A, b = 13.599(1) A, c = 18.983(1) A, β = 99.08(1)°. The crystallographic investigation reveals a complex three-dimensional structure based on hydrogen-bond interactions between the aqua ligands coordinated to the nickel atoms and the oxalato groups arising from the [Cr(bipy)(C 2 O 4 ) 2 ] - anions. The π-π stacking interactions (∼3.4 A) between the 2,2-bipyridine ligands coordinated to the chromium(III) ions play an important role in sustaining the supramolecular solid-state architecture. The value of the Χ M T product at T 289 K (6.5 cm 3 mol - 1 K) corresponds to the expected value for four uncorrelated local spins. The electronic spectrum of 1 displays the characteristic features of both hexacoordinated Ni(II) and Cr(III) ions.
Journal of The Chemical Society-dalton Transactions, 1995
ABSTRACT
Polish Journal of Chemistry, 1999
Acta crystallographica, 1978
LiSO3F is, monoclinic, space group C2/m, Z = 4, with a = 8.54 (2), b = 7.62 (I), c = 4.98 (2) A, ... more LiSO3F is, monoclinic, space group C2/m, Z = 4, with a = 8.54 (2), b = 7.62 (I), c = 4.98 (2) A, fl= 90-0 (3)°; D,,, = 2.20, D C = 2.17 g cm-3. The structure, which was refined to R-0.085 for 332 densitometer intensities, consists of Li + and SO3Fions arranged in alternating cationic and anionic layers. The layers are bound into a three-dimensional structure by Li-O bonds. The SO3F group is tetrahedral with a fixed position for the F atom. The whole group is coordinated by eight Li atoms in a slightly distorted cubic arrangement. Li atoms are coordinated tetrahedrally by four O atoms. Two LiO 4 tetrahedra share a common edge to form Li206 groups. The important bond lengths are SO 1.455 and 1.424, S-F 1.555, and Li-O 2-045 and 1.903 A. The e.s.d.'s are 0.004-0.03 A for the lengths and 0.2-0.9 ° for the angles.
Chemischer Informationsdienst, Sep 21, 1971
Acta Crystallographica Section A, Aug 8, 1996
Alar<>e number of new compounds have been synthesised and structurally ch;•acte1ized in the A-MoP... more Alar<>e number of new compounds have been synthesised and structurally ch;•acte1ized in the A-MoP -0 system where A is an alkali or alkaline-earth metal and Mo is in the oxidation states below VI. In contrast to the rich stmctural chemistry of molybdenum phosphates, little is known about their arsenate analogues. As a part of our research program to study the str1.1ctural chemistry of transistion-metal arsenates, we began to synthesise new compounds in the A-MoV1-AsY-O system usin~ hydrothenmu techniques. By incorporating either organic or hydrated morgarric cations in the hydrothennal reactions, novel frameworks have been produced. In tins presentation, t11e synthesis and crystal structures of three se1ies of molybdenum(VI) arsenates will be given. They include: (1) A 2 Mo20 5 (HAs0 4)2•H20 (A = Cs and CsHsNH); (2) As[Mo~<?l2 (OH)hAs0 4 •2H 2 0 (A = Rb and Cs), and the tl1ermal decompos1t:J.on product Cs7(Mo03)02As04: and (3) SrMo03(HAs04)•H20 and Ba(Mo0 3) 6 (As0 4)4(H 2 0h. Structural relationship an1ong some oftl1ese molybdenum arsenates is also discussed.
Chemischer Informationsdienst, Jan 16, 1979
Acta Crystallographica Section C-crystal Structure Communications, Jan 15, 1993
ABSTRACT
Zeitschrift für anorganische und allgemeine Chemie, Nov 1, 1994
Neue O,O′,O″,O‴-Tetratolyl- und Diphenylditolyl-ester der μ-Imido-diphosphorsaure und ihres Monot... more Neue O,O′,O″,O‴-Tetratolyl- und Diphenylditolyl-ester der μ-Imido-diphosphorsaure und ihres Monothio- und Dithioderivates wurden synthetisiert, in ihren Eigenschaften mit den bekannten Phenylestern verglichen und 1H-, 13C- und 31P-NMR-spektroskopisch untersucht. Die Kristall- und Molekulstrukturen des O,O′,O″,O‴-Tetrakis-(2-methyl-phenyl)-μ-imido-diphosphats, 1b, sowie der entsprechenden ortho-, meta-, und para-Tolylester der μ-Imido-monothiodiphosphorsaure (2b, 2c, 2d) konnten gelost werden. Alle Verbindungen bilden uber NH…O-Wasserstoffbrucken Dimere, die auch in unpolaren Losungsmitteln erhalten bleiben. Die Bindungsabstande um die P-Atome nehmen mit sinkender Elektronegativitat der Substituenten zu. Durch 13C{1H, 31P}- Tripelresonanzexperimente wurde das Vorzeichen der 2JPNP- Kopplungskonstanten fur einige Verbindungen bestimmt. Bei Substitution von Phosphoryl- durch Thiophosphorylgruppen werden diese Konstanten negativer. Tetraarylesters of μ-Imido-Diphosphoric Acid and its Thio Derivatives — Structure Investigations New O,O′,O″,O‴-tetratolyl- and ditolyl-diphenylesters of the μ-imido-diphosphoric acid and its mono and dithio derivatives were synthesized, compared with the corresponding tetraphenylesters and investigated by 1H, 13C, and 31P NMR spectroscopy and X-ray crystal structure analysis. Structures of the O,O′,O″,O‴-tetrakis-(2-methyl-phenyl)-μ-imidodiphosphate, 1b, as well as of the corresponding ortho-, meta- and para-tolylesters of the μ-imido-monothiodiphosphoric acid (2a, 2b, 2c) were determined. All the compounds form dimers via NH…O hydrogen bonds in the crystal as well as in nonpolar solvents. The distances around the phosphorus atoms rise with decreasing electronegativity of the phosphorus substituents. Signs of the 2JPNP coupling constants were determined by 13C{1H, 31P} triple resonance experiments for some compounds. These constants become more negative owing to substitution of a phosphoryl by a thiophosphoryl group.