1,1,3,3-Tetramethylurea

Frampton, C. S.; Parkes, K. E. B.

doi:10.1107/s0108270196011146

Cited by 18 publications

(16 citation statements)

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“…The molecule of TetMTU is shown in Fig. 14. Although the compound crystallizes in C2/c, the same space group as tetramethylurea (Frampton & Parkes, 1996), and both compounds display crystallographic twofold symmetry, they are not isotypic. There are, however, some common features that are noteworthy.…”

Section: Tetramethylthioureamentioning

confidence: 99%

Methylthioureas and their morpholine and dioxane adducts; hydrogen-bonding patterns

Jones

Taouss

Teschmit

et al. 2013

Acta Crystallogr Sect B

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We have redetermined the known structures of (i) methylthiourea (MTU) and (ii) 1,1-dimethylthiourea (1,1-DMTU), and investigated the structure of 1,3-dimethylthiourea (1,3-DMTU), which was however severely disordered. We report the structures of crystalline adducts of (iii) MTU with morpholine (1:1), (iv) 1,1-DMTU with 1,4-dioxane (2:1) and (v) 1,3-DMTU with 1,4-dioxane (2:1). Finally, (vi) we determined the structure of tetramethylthiourea (TetMTU). (i) In both independent molecules of MTU, the methyl group is trans to the C=S group across the C-N bond. The two molecules are connected to form an R2(2)(8) dimer by mutual N-H...S=C interactions. The packing involves six N-H...S=C interactions and is three-dimensional. (ii) The packing of the MTU-morpholine adduct is a layer structure, within which both molecules form linear aggregates parallel to the b axis. (iii) The packing of 1,1-DMTU involves N-H...S=C hydrogen bonds forming a corrugated layer structure. (iv) In the 2:1 adduct between 1,1-DMTU and 1,4-dioxane, the DMTU molecule occupies a general position whereas the dioxane molecule lies across an inversion centre. The crystal packing involves chains of alternating 1,1-DMTU R2(2)(8) dimers and dioxanes, both across inversion centres. (v) In the 2:1 adduct between 1,3-DMTU and dioxane, the 1,3-DMTU molecule occupies a general position, while the dioxane molecule lies across an inversion centre. One methyl group of the DMTU is trans and one cis to the sulfur across the corresponding C-N bond. The molecules form chains of alternating 1,3-DMTU R2(2)(8) dimers and dioxanes, both across inversion centres. Crystals of the 2:1 adduct between 1,3-DMTU and morpholine were also obtained, and were isotypic with the dioxane adduct. The morpholine molecule is disordered across the inversion centre. (vi) The molecule of TetMTU displays crystallographic twofold symmetry. Significant distortions reflect the steric pressure between methyl groups trans to sulfur. The packing of TetMTU involves only a weak hydrogen bond, C-Hmethyl...S, which connects the molecules to form layers.

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Section: Tetramethylthioureamentioning

confidence: 99%

Methylthioureas and their morpholine and dioxane adducts; hydrogen-bonding patterns

Jones

Taouss

Teschmit

et al. 2013

Acta Crystallogr Sect B

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“…Interessant ist ein Vergleich der Strukturparameter von Verbindung 1 mit denen des Molekülkomplexes [Cl 3 Al(TMH)] 6, die zusammen mit denen des nichtkoordinierten N , N ′‐Tetramethylharnstoffmoleküls 11 in den Formelbildern A , B und C dargestellt sind (Schema ).…”

Section: Ergebnisse Und Diskussionunclassified

“…Unbeeinflusst hiervon bleiben in beiden Komplexen die planare Umgebung der Stickstoffatome der Ligandenmoleküle mit Winkelsummen von 357.2 bis 359.9° in 1 und mit 358.4 und 359.7° in [Cl 3 Al(TMH)] 6. Dagegen sind die Abweichungen von der Planarität der NC 3 ‐Ebenen in der Struktur des nichtkoordinierten Tetramethylharnstoff‐Moleküls (Strukturbestimmung bei 262 K 11) mit 354.1° deutlich größer. Dagegen zeigen die drei Formelbilder in Schema planare Umgebung des mittleren Kohlenstoffatoms mit Winkelsummen von 359.9, 360.4 und 360.0° an, bei allerdings jeweils deutlich veränderten Einzelwinkeln.…”

Section: Ergebnisse Und Diskussionunclassified

Tetra(N,N′‐tetramethylharnstoff)‐Beryllium‐Triiodid, [Be(TMH)₄](I₃)₂

Neumüller¹,

Dehnicke²

2010

Zeitschrift anorg allge chemie

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Tetra(N,N′‐tetramethylurea)‐beryllium‐triiodide, [Be(TMU)4](I3)2 (1) was prepared from beryllium powder and iodine in N,N′‐tetramethylurea to give orange crystals, which were characterized by X‐ray diffraction and IR spectroscopy. Compound 1 crystallizes monoclinically in the space group C2/c with four formula units per unit cell. Lattice dimensions at 100(2) K: a = 1906.6(1), b = 1185.7(1), c = 1895.0(1) pm, β = 113.60(1) °, R1 = 0.0291. The structure of 1 consists of distorted tetrahedral cations [Be(TMU)4]2+ with Be–O bond lengths of 162.5(5) and 160.8(5) pm and triiodide ions without site symmetry.

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“…The short C9ÐN bonds (Table 1) indicate a signi®cant double-bond character, but they are slightly longer than those in the corresponding NH 2 compounds (II) and (III) [1.306 (2)±1.317 (2) A Ê ]. The corresponding CÐN bond lengths in urea (Zavodnik et al, 1999) and N,N,N H ,N H -tetramethylurea (Frampton & Parkes, 1996) are 1.343 and 1.3706 (13) A Ê , respectively. A comparison with the corresponding thiourea derivatives cannot be considered here, because free thiourea undergoes ferroelectric phase transitions (Takahashi et al, 1990) and the crystal structure of N,N,N H ,N H -tetramethylthiourea is not available in the literature.…”

Section: Commentmentioning

confidence: 99%

Multipole refinement of 2-(indol-3-yl)-1,1,3,3-tetramethylthiouronium nitrate

et al. 2008

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The cation of the title compound, C13H18N3S+·NO3−, consists of two subunits, viz. a planar indole moiety and a nonplanar thiouronium moiety. An isolated intermolecular hydrogen bond connects the cation with the nitrate anion. The crystal packing is additionally characterized by short intermolecular contacts between parallel indole systems. A topological analysis of the electron density revealed C—S single bonds and partial double bonding in the N—C—N group.

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1,1,3,3-Tetramethylurea

Cited by 18 publications

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Methylthioureas and their morpholine and dioxane adducts; hydrogen-bonding patterns

Methylthioureas and their morpholine and dioxane adducts; hydrogen-bonding patterns

Tetra(N,N′‐tetramethylharnstoff)‐Beryllium‐Triiodid, [Be(TMH)₄](I₃)₂

Multipole refinement of 2-(indol-3-yl)-1,1,3,3-tetramethylthiouronium nitrate

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1,1,3,3-Tetramethylurea

Cited by 18 publications

References 0 publications

Methylthioureas and their morpholine and dioxane adducts; hydrogen-bonding patterns

Methylthioureas and their morpholine and dioxane adducts; hydrogen-bonding patterns

Tetra(N,N′‐tetramethylharnstoff)‐Beryllium‐Triiodid, [Be(TMH)4](I3)2

Multipole refinement of 2-(indol-3-yl)-1,1,3,3-tetramethylthiouronium nitrate

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About

Tetra(N,N′‐tetramethylharnstoff)‐Beryllium‐Triiodid, [Be(TMH)₄](I₃)₂