The crystal and molecular structure of ammonium titanyl oxalate

G.M.H. van de Velde, Sybolt Harkema, P.J. Gellings

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Abstract

Ammonium titanyl oxalate monohydrate, (NH4)2 TiO(C2O4)2·H2O, is monoclinic with cell parameters A = 13.473(2), B = 11.329(1), C = 17.646(2) Å, β = 126.66(1)°. The space group is P21/c with Z = 8, dc = 1.808 g cm−3 and dm = 1.80 g cm−3. The crystal structure was determined from single-crystal diffractometer data and refined by least-squares methods using isotropic thermal parameters. The conventional R factor was 7.0% for 2466 used reflections. The anions consist of cyclic tetranuclear complexes [TiO O (C2O4)2]48− with symmetry. The titanium atoms are six-coordinated with two bridging oxygen atoms cis to one another and four oxygen atoms of bidentate oxalate groups, together forming a distorted octahedron. The titanium atoms of the tetramer are linked through oxygen atoms at two neighbouring apices of each octahedron. The actual name of the compound should therefore be: ammonium cyclotetra-di-μ-oxo-cis-dioxalatotitanate(IV)tetrahydrate. The di-μ-oxo-tetratitanium unit is an eight-membered ---O---Ti---O--- ring with Ti-O distances of successively 1.840(7), 1.785(7) and 1.855(6), 1.788(8) Å, repeated by the centre of symmetry, and the orientation of the atoms suggests the presence of dπ---pπ 3-center 2-electron bonds in each Ti---O---Ti set. The Ti---O distances trans to the bridging oxygen atoms are much longer: 2.060(7), 2.101(7), 2.081(7) and 2.116(7) Å respectively, as is to be expected from the charge displacement due to the dπ---pπ bonding. Most O---Ti---O angles in the distorted octahedra differ considerably from 90°. As was found by difference Fourier synthesis and thermal analysis, half of the crystal water is held very loosely compared to the other half.
Original languageUndefined
Pages (from-to)243-252
JournalInorganica chimica acta
Volume11
DOIs
Publication statusPublished - 1974

Keywords

  • IR-68025

Cite this

van de Velde, G.M.H. ; Harkema, Sybolt ; Gellings, P.J. / The crystal and molecular structure of ammonium titanyl oxalate. In: Inorganica chimica acta. 1974 ; Vol. 11. pp. 243-252.
@article{1c8c900f67254db5bb92421f28f4a4e3,
title = "The crystal and molecular structure of ammonium titanyl oxalate",
abstract = "Ammonium titanyl oxalate monohydrate, (NH4)2 TiO(C2O4)2·H2O, is monoclinic with cell parameters A = 13.473(2), B = 11.329(1), C = 17.646(2) {\AA}, β = 126.66(1)°. The space group is P21/c with Z = 8, dc = 1.808 g cm−3 and dm = 1.80 g cm−3. The crystal structure was determined from single-crystal diffractometer data and refined by least-squares methods using isotropic thermal parameters. The conventional R factor was 7.0{\%} for 2466 used reflections. The anions consist of cyclic tetranuclear complexes [TiO O (C2O4)2]48− with symmetry. The titanium atoms are six-coordinated with two bridging oxygen atoms cis to one another and four oxygen atoms of bidentate oxalate groups, together forming a distorted octahedron. The titanium atoms of the tetramer are linked through oxygen atoms at two neighbouring apices of each octahedron. The actual name of the compound should therefore be: ammonium cyclotetra-di-μ-oxo-cis-dioxalatotitanate(IV)tetrahydrate. The di-μ-oxo-tetratitanium unit is an eight-membered ---O---Ti---O--- ring with Ti-O distances of successively 1.840(7), 1.785(7) and 1.855(6), 1.788(8) {\AA}, repeated by the centre of symmetry, and the orientation of the atoms suggests the presence of dπ---pπ 3-center 2-electron bonds in each Ti---O---Ti set. The Ti---O distances trans to the bridging oxygen atoms are much longer: 2.060(7), 2.101(7), 2.081(7) and 2.116(7) {\AA} respectively, as is to be expected from the charge displacement due to the dπ---pπ bonding. Most O---Ti---O angles in the distorted octahedra differ considerably from 90°. As was found by difference Fourier synthesis and thermal analysis, half of the crystal water is held very loosely compared to the other half.",
keywords = "IR-68025",
author = "{van de Velde}, G.M.H. and Sybolt Harkema and P.J. Gellings",
year = "1974",
doi = "10.1016/S0020-1693(00)93716-2",
language = "Undefined",
volume = "11",
pages = "243--252",
journal = "Inorganica chimica acta",
issn = "0020-1693",
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}

The crystal and molecular structure of ammonium titanyl oxalate. / van de Velde, G.M.H.; Harkema, Sybolt; Gellings, P.J.

In: Inorganica chimica acta, Vol. 11, 1974, p. 243-252.

Research output: Contribution to journalArticleAcademic

TY - JOUR

T1 - The crystal and molecular structure of ammonium titanyl oxalate

AU - van de Velde, G.M.H.

AU - Harkema, Sybolt

AU - Gellings, P.J.

PY - 1974

Y1 - 1974

N2 - Ammonium titanyl oxalate monohydrate, (NH4)2 TiO(C2O4)2·H2O, is monoclinic with cell parameters A = 13.473(2), B = 11.329(1), C = 17.646(2) Å, β = 126.66(1)°. The space group is P21/c with Z = 8, dc = 1.808 g cm−3 and dm = 1.80 g cm−3. The crystal structure was determined from single-crystal diffractometer data and refined by least-squares methods using isotropic thermal parameters. The conventional R factor was 7.0% for 2466 used reflections. The anions consist of cyclic tetranuclear complexes [TiO O (C2O4)2]48− with symmetry. The titanium atoms are six-coordinated with two bridging oxygen atoms cis to one another and four oxygen atoms of bidentate oxalate groups, together forming a distorted octahedron. The titanium atoms of the tetramer are linked through oxygen atoms at two neighbouring apices of each octahedron. The actual name of the compound should therefore be: ammonium cyclotetra-di-μ-oxo-cis-dioxalatotitanate(IV)tetrahydrate. The di-μ-oxo-tetratitanium unit is an eight-membered ---O---Ti---O--- ring with Ti-O distances of successively 1.840(7), 1.785(7) and 1.855(6), 1.788(8) Å, repeated by the centre of symmetry, and the orientation of the atoms suggests the presence of dπ---pπ 3-center 2-electron bonds in each Ti---O---Ti set. The Ti---O distances trans to the bridging oxygen atoms are much longer: 2.060(7), 2.101(7), 2.081(7) and 2.116(7) Å respectively, as is to be expected from the charge displacement due to the dπ---pπ bonding. Most O---Ti---O angles in the distorted octahedra differ considerably from 90°. As was found by difference Fourier synthesis and thermal analysis, half of the crystal water is held very loosely compared to the other half.

AB - Ammonium titanyl oxalate monohydrate, (NH4)2 TiO(C2O4)2·H2O, is monoclinic with cell parameters A = 13.473(2), B = 11.329(1), C = 17.646(2) Å, β = 126.66(1)°. The space group is P21/c with Z = 8, dc = 1.808 g cm−3 and dm = 1.80 g cm−3. The crystal structure was determined from single-crystal diffractometer data and refined by least-squares methods using isotropic thermal parameters. The conventional R factor was 7.0% for 2466 used reflections. The anions consist of cyclic tetranuclear complexes [TiO O (C2O4)2]48− with symmetry. The titanium atoms are six-coordinated with two bridging oxygen atoms cis to one another and four oxygen atoms of bidentate oxalate groups, together forming a distorted octahedron. The titanium atoms of the tetramer are linked through oxygen atoms at two neighbouring apices of each octahedron. The actual name of the compound should therefore be: ammonium cyclotetra-di-μ-oxo-cis-dioxalatotitanate(IV)tetrahydrate. The di-μ-oxo-tetratitanium unit is an eight-membered ---O---Ti---O--- ring with Ti-O distances of successively 1.840(7), 1.785(7) and 1.855(6), 1.788(8) Å, repeated by the centre of symmetry, and the orientation of the atoms suggests the presence of dπ---pπ 3-center 2-electron bonds in each Ti---O---Ti set. The Ti---O distances trans to the bridging oxygen atoms are much longer: 2.060(7), 2.101(7), 2.081(7) and 2.116(7) Å respectively, as is to be expected from the charge displacement due to the dπ---pπ bonding. Most O---Ti---O angles in the distorted octahedra differ considerably from 90°. As was found by difference Fourier synthesis and thermal analysis, half of the crystal water is held very loosely compared to the other half.

KW - IR-68025

U2 - 10.1016/S0020-1693(00)93716-2

DO - 10.1016/S0020-1693(00)93716-2

M3 - Article

VL - 11

SP - 243

EP - 252

JO - Inorganica chimica acta

JF - Inorganica chimica acta

SN - 0020-1693

ER -