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Redetermination of the crystal structure of di ­ methyl ­ bis ­ [2,4-penta ­ nedionato(1 − )- κ 2 O 2 , O 4 ]tin(IV)

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ABSTRACT

12: The redetermination of the title compound, [Sn(CH3)2(C5H7O2)2] or SnMe2(acac)2, from CCD data recorded at 100 K basically confirms the previous study based on integrated film data recorded at room temperature [Miller & Schlemper (1972 ▸). Inorg. Chem., 677–681], but reveals a remarkable shrinkage of the a axis [7.12 (1) > 6.7694 (4) Å]. The mol­ecule belongs to point group Ci with the SnIV atom on a centre of inversion. The SnIV atom shows a slightly distorted octa­hedral coordination sphere with the methyl groups in trans positions and a Sn—C bond length of 2.115 (2) Å which may serve as a standard value for an Sn—CH3 bond of an octa­hedrally coordinated SnIV atom. The Sn—O bonds involving the two carbonyl groups of the acetyl­acetonate ligand are of equal length [2.180 (1) and 2.183 (1) Å], as are the C=O [1.273 (1) and 1.274 (1) Å] and C—C bond lengths [1.393 (2) and 1.400 (2) Å]. The acetyl­acetonate ligand deviates considerably from planarity, with a dihedral angle of 5.57 (9)° between the least-squares planes of the two acetone moieties. The four O atoms of the two symmetry-related acetyl­acetonate ligands are arranged in a nearly quadratic rectangle. Weak C—H⋯O inter­actions consolidate the crystal packing.

No MeSH data available.


The mol­ecular structure of the title compound, showing the atom-labeling scheme of the asymmetric unit. Displacement ellipsoids are drawn at the 50% probability level.
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fig1: The mol­ecular structure of the title compound, showing the atom-labeling scheme of the asymmetric unit. Displacement ellipsoids are drawn at the 50% probability level.

Mentions: The Sn atom is octa­hedrally coordinated with the two methyl groups in a trans position (Fig. 1 ▸, Table 1 ▸). The Sn—C bond shows a length of 2.115 (2) Å and is significantly shorter than the value [2.14 (2) Å] obtained by Miller & Schlemper (1972 ▸). Because of the higher coordination number, the value differs to some extent from the value of 2.099 (2) Å for Sn with a coordination number of four as observed in di­methyl­dithio­cyanato tin(IV) (Britton, 2006 ▸). The two bonds between the Sn atom and the two different O atoms of the acetyl­acetonate ligand are of equal length [2.180 (1)/2.183 (1) Å]. In accordance with the almost symmetrical bonding of the acetyl­acetonate ligand to tin, C—O [1.273 (2)/1.274 (2) Å] and C—C [1.393 (2)/1.400 (2) Å] bonds of the 1,3-diketonate skeleton are of equal length. Although these values are typical for a delocalized π system, the atoms in question show a significant deviation from planarity at the central C2 atom, resulting in a dihedral angle of 5.57 (9)° between the least-squares planes defined by O1/C1/C2/C3 [deviations from planarity: 0.003 (1), −0.007 (1), 0.002 (1), 0.002 (1) Å, respectively] and O2/C3/C2/C4 [deviations from planarity: 0.002 (1), −0.004 (1), 0.002 (1), 0.001 (2) Å, respectively] (Fig. 2 ▸). Moreover, all bond angles in the six-membered chelate ring are considerably larger [125.61 (9)° at O1, 126.2 (1)° at C1, 128.4 (1)° at C2, 126.07 (13)° at C3, 125.68 (9)° at O2] than expected for sp2-hybridized atoms, with exception of the bond angle at Sn1 that amounts to 85.99 (4)°. The four O atoms of the two symmetry-related acetyl­acetonate ligands around the Sn atom form a planar rectangle with similar edge lengths [O1⋯O2 = 2.975 (1)/O1⋯O1 = 3.191 (1) Å], and almost right angles [89.9 (1)° at O1 and 90.1 (1)° at O2]. This plane is nearly perpendicular to the axis through the two methyl groups [deviation: 0.44 (2)°] but constitutes a dihedral angle of 10.2 (1)° with the least-squares plane through the two carbonyl groups of the acetyl­acetonate ligand [deviations from planarity: O1 = 0.006 (1), C1 = −0.007 (1), O2 = −0.006 (1) Å, C3 = 0.007 (1) Å] (Fig. 3 ▸).


Redetermination of the crystal structure of di ­ methyl ­ bis ­ [2,4-penta ­ nedionato(1 − )- κ 2 O 2 , O 4 ]tin(IV)
The mol­ecular structure of the title compound, showing the atom-labeling scheme of the asymmetric unit. Displacement ellipsoids are drawn at the 50% probability level.
© Copyright Policy - open-access
Related In: Results  -  Collection

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Show All Figures
getmorefigures.php?uid=PMC5382601&req=5

fig1: The mol­ecular structure of the title compound, showing the atom-labeling scheme of the asymmetric unit. Displacement ellipsoids are drawn at the 50% probability level.
Mentions: The Sn atom is octa­hedrally coordinated with the two methyl groups in a trans position (Fig. 1 ▸, Table 1 ▸). The Sn—C bond shows a length of 2.115 (2) Å and is significantly shorter than the value [2.14 (2) Å] obtained by Miller & Schlemper (1972 ▸). Because of the higher coordination number, the value differs to some extent from the value of 2.099 (2) Å for Sn with a coordination number of four as observed in di­methyl­dithio­cyanato tin(IV) (Britton, 2006 ▸). The two bonds between the Sn atom and the two different O atoms of the acetyl­acetonate ligand are of equal length [2.180 (1)/2.183 (1) Å]. In accordance with the almost symmetrical bonding of the acetyl­acetonate ligand to tin, C—O [1.273 (2)/1.274 (2) Å] and C—C [1.393 (2)/1.400 (2) Å] bonds of the 1,3-diketonate skeleton are of equal length. Although these values are typical for a delocalized π system, the atoms in question show a significant deviation from planarity at the central C2 atom, resulting in a dihedral angle of 5.57 (9)° between the least-squares planes defined by O1/C1/C2/C3 [deviations from planarity: 0.003 (1), −0.007 (1), 0.002 (1), 0.002 (1) Å, respectively] and O2/C3/C2/C4 [deviations from planarity: 0.002 (1), −0.004 (1), 0.002 (1), 0.001 (2) Å, respectively] (Fig. 2 ▸). Moreover, all bond angles in the six-membered chelate ring are considerably larger [125.61 (9)° at O1, 126.2 (1)° at C1, 128.4 (1)° at C2, 126.07 (13)° at C3, 125.68 (9)° at O2] than expected for sp2-hybridized atoms, with exception of the bond angle at Sn1 that amounts to 85.99 (4)°. The four O atoms of the two symmetry-related acetyl­acetonate ligands around the Sn atom form a planar rectangle with similar edge lengths [O1⋯O2 = 2.975 (1)/O1⋯O1 = 3.191 (1) Å], and almost right angles [89.9 (1)° at O1 and 90.1 (1)° at O2]. This plane is nearly perpendicular to the axis through the two methyl groups [deviation: 0.44 (2)°] but constitutes a dihedral angle of 10.2 (1)° with the least-squares plane through the two carbonyl groups of the acetyl­acetonate ligand [deviations from planarity: O1 = 0.006 (1), C1 = −0.007 (1), O2 = −0.006 (1) Å, C3 = 0.007 (1) Å] (Fig. 3 ▸).

View Article: PubMed Central - HTML - PubMed

ABSTRACT

12: The redetermination of the title compound, [Sn(CH3)2(C5H7O2)2] or SnMe2(acac)2, from CCD data recorded at 100 K basically confirms the previous study based on integrated film data recorded at room temperature [Miller & Schlemper (1972 ▸). Inorg. Chem., 677–681], but reveals a remarkable shrinkage of the a axis [7.12 (1) > 6.7694 (4) Å]. The mol­ecule belongs to point group Ci with the SnIV atom on a centre of inversion. The SnIV atom shows a slightly distorted octa­hedral coordination sphere with the methyl groups in trans positions and a Sn—C bond length of 2.115 (2) Å which may serve as a standard value for an Sn—CH3 bond of an octa­hedrally coordinated SnIV atom. The Sn—O bonds involving the two carbonyl groups of the acetyl­acetonate ligand are of equal length [2.180 (1) and 2.183 (1) Å], as are the C=O [1.273 (1) and 1.274 (1) Å] and C—C bond lengths [1.393 (2) and 1.400 (2) Å]. The acetyl­acetonate ligand deviates considerably from planarity, with a dihedral angle of 5.57 (9)° between the least-squares planes of the two acetone moieties. The four O atoms of the two symmetry-related acetyl­acetonate ligands are arranged in a nearly quadratic rectangle. Weak C—H⋯O inter­actions consolidate the crystal packing.

No MeSH data available.