Bis(acetyl­acetonato-κ2 O,O′)(pyridine-κN)zinc(II)

Sanjaya Brahma; M Srinidhi; S A Shivashankar; T Narasimhamurthy; R S Rathore

doi:10.1107/S1600536811019854

. 2011 May 28;67(Pt 6):m819. doi: 10.1107/S1600536811019854

Bis(acetylacetonato-κ² O,O′)(pyridine-κN)zinc(II)

Sanjaya Brahma ^a, M Srinidhi ^b, S A Shivashankar ^a, T Narasimhamurthy ^a, R S Rathore ^c,^*

PMCID: PMC3120430 PMID: 21754690

Abstract

In the title compound, [Zn(C₅H₇O₂)₂(C₅H₅N)], the metal atom has square-pyramidal coordination geometry with the basal plane defined by the four O atoms of the chelating acetylacetonate ligands and with the axial position occupied by the pyridine N atom. The crystal packing is characterized by a C—H⋯O hydrogen-bonded ribbon structure approximately parallel to [10 Inline graphic ].

Related literature

For related structures, see: Brahma et al. (2008 ▶); Neelgund et al. (2007 ▶); Urs et al. (2001 ▶).

Experimental

Crystal data

[Zn(C₅H₇O₂)₂(C₅H₅N)]
M _r = 342.68
Monoclinic,
a = 7.846 (5) Å
b = 27.047 (4) Å
c = 8.199 (5) Å
β = 117.984 (3)°
V = 1536.5 (14) Å³
Z = 4
Mo Kα radiation
μ = 1.61 mm⁻¹
T = 295 K
0.32 × 0.23 × 0.12 mm

Data collection

Bruker APEXII CCD area-detector diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2004 ▶) T _min = 0.64, T _max = 0.83
10840 measured reflections
2939 independent reflections
2568 reflections with I > 2σ(I)
R _int = 0.074

Refinement

R[F ² > 2σ(F ²)] = 0.040
wR(F ²) = 0.106
S = 0.99
2939 reflections
194 parameters
H-atom parameters constrained
Δρ_max = 0.36 e Å⁻³
Δρ_min = −0.74 e Å⁻³

Data collection: APEX2 (Bruker, 2004 ▶); cell refinement: SAINT-Plus (Bruker, 2004 ▶); data reduction: SAINT-Plus; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: ORTEP-3 (Farrugia, 1997 ▶) and PLATON (Spek, 2009 ▶); software used to prepare material for publication: SHELXL97 and PLATON.

Supplementary Material

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536811019854/ng5159sup1.cif

e-67-0m819-sup1.cif^{(19.4KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536811019854/ng5159Isup2.hkl

e-67-0m819-Isup2.hkl^{(141.3KB, hkl)}

Additional supplementary materials: crystallographic information; 3D view; checkCIF report

Table 1. Hydrogen-bond geometry (Å, °).

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
C13—H13⋯O2ⁱ	0.93	2.50	3.141 (5)	126
C14—H14⋯O3ⁱⁱ	0.93	2.59	3.500 (5)	165
C4—H4A⋯O4ⁱⁱⁱ	0.96	2.41	3.304 (5)	155

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Symmetry codes: (i) Inline graphic ; (ii) ; (iii) .

Acknowledgments

We acknowledge the CCD facility, set up under the IRHPA–DST program at the Indian Institute of Science, Bangalore. SB thanks the Council of Scientific and Industrial research (CSIR), New Delhi, for the award of research associateship. RSR gratefully acknowledges the CSIR for funding under the scientist’s pool scheme.

supplementary crystallographic information

Comment

The title compound, [Zn(II)(C₅H₇O₂)₂(C₅H₅N)], is a mixed-ligand metal-organic precursor for chemical vapour deposition, with the Zn atom being five coordinate. Metal-organic (MO) complexes have been widely employed as precursors for chemical vapour deposition (CVD) for the growth of various thin films. The title complex, (I), has been synthesized and discussed here. Several such MOCVD precursors have been previously synthesized and characterized (Urs et al., 2001; Neelgund et al., 2007; Brahma et al., 2008; and references therein).

The structure of (I) with adopted atom-numbering scheme is shown in Fig 1. The coordination geometry around Zn(II) is square-pyramidal with the basal plane defined by four O atoms from two chelating acetylacetonate (acac) ligands and the axial position occupied by N atom from pyridine ring. The five-membered ring formed by acetylacetonate and Zn atom is significantly non-planar.

The geometric parameters for observed short contacts are listed in Table 1. Crystal packing diagram is shown in Fig 2. The intermolecular C13—H13···O2 and C14—H14..O3 interactions, combined together generate C—H···O bonded ribbon structure that is approximately parallel to [101]-direction. A short C4—H4A···O4 contact associated with methyl group is also observed in the crystal.

Experimental

The title complex was synthesized from their precursor hydrate complex, i.e. bis(acetylacetonato)aquazinc(II). Acetylacetone (10 mmol, 1.02 ml) was added to zinc diacetate dihydrate solution (5 mmol, 1.099 g; 30% ethanol-water mixture). Potassium hydroxide (KOH) solution (10 mmol, 0.56 g; 30% ethanol-water mixture) was added gradually to achieve a pH of 6–7. After stirring at room temperature for 1 hr, the mixture yielded a precipitate, which was filtered off and dried in a vacuum. The product was recrystallized from ethanol, giving a pure hydrate complex. To obtain the title complex from the hydrate, an ethanol solution of the hydrate was prepared and added in a (1:1) molar ratio to ethanol solutions of pyridine and stirred for 12 hr. Single crystals suitable for X-ray diffraction were grown by slow evaporation of the resultant solution in ethanol at low temperature.