Dichloridobis(7-amino-2,4-dimethyl-1,8-naphthyridine-κ2 N,N′)cobalt(II) methanol disolvate

Shouwen Jin; Ying Sun

doi:10.1107/S160053680706494X

. 2007 Dec 6;64(Pt 1):m136–m137. doi: 10.1107/S160053680706494X

Dichloridobis(7-amino-2,4-dimethyl-1,8-naphthyridine-κ² N,N′)cobalt(II) methanol disolvate

Shouwen Jin ^a,^*, Ying Sun ^b

PMCID: PMC2915083 PMID: 21200493

Abstract

The title compound, [CoCl₂(C₁₀H₁₁N₃)₂]·2CH₃OH, crystallizes with an elongated Co coordination polyhedron in a very distorted octahedral geometry. Both naphthyridine ligands coordinate to the Co atom via two N atoms in a bidentate chelating mode. The remaining coordination sites are occupied by two Cl atoms. Two uncoordinated solvent methanol molecules are hydrogen bonded to the Cl atoms. Additional N—H⋯O, C—H⋯Cl and N—H⋯Cl hydrogen bonds, and π–π stacking interactions [centroid–centroid distance 3.664 (4) Å], give rise to a three-dimensional network structure.

Related literature

For related literature, see: Bayer (1979 ▶); Che et al. (2001 ▶); Gavrilova & Bosnich (2004 ▶); Harvey et al. (2004 ▶); Jin et al. (2007 ▶); Kukrek et al. (2006 ▶); Mintert & Sheldrick (1995a ▶,b ▶); Oskui et al. (1999 ▶); Oskui & Sheldrick (1999 ▶).

Experimental

Crystal data

[CoCl₂(C₁₀H₁₁N₃)₂]·2CH₄O
M _r = 540.35
Triclinic,
a = 9.694 (3) Å
b = 10.651 (3) Å
c = 14.154 (4) Å
α = 79.523 (4)°
β = 78.548 (4)°
γ = 65.697 (4)°
V = 1297.2 (6) Å³
Z = 2
Mo Kα radiation
μ = 0.90 mm⁻¹
T = 298 (2) K
0.27 × 0.21 × 0.18 mm

Data collection

Bruker SMART APEX CCD diffractometer
Absorption correction: multi-scan (SADABS; Sheldrick, 1996 ▶) T _min = 0.794, T _max = 0.855
6885 measured reflections
4521 independent reflections
2999 reflections with I > 2σ(I)
R _int = 0.021

Refinement

R[F ² > 2σ(F ²)] = 0.047
wR(F ²) = 0.125
S = 1.04
4521 reflections
300 parameters
H-atom parameters constrained
Δρ_max = 0.45 e Å⁻³
Δρ_min = −0.27 e Å⁻³

Data collection: SMART (Bruker, 1997 ▶); cell refinement: SAINT (Bruker, 1997 ▶); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 1997a ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997a ▶); molecular graphics: SHELXTL (Sheldrick, 1997b ▶); software used to prepare material for publication: SHELXTL.

Supplementary Material

Crystal structure: contains datablocks global, I. DOI: 10.1107/S160053680706494X/zl2083sup1.cif

e-64-0m136-sup1.cif^{(25.2KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S160053680706494X/zl2083Isup2.hkl

e-64-0m136-Isup2.hkl^{(221.5KB, 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
O2—H2⋯Cl1ⁱ	0.82	2.35	3.162 (4)	172
O1—H1⋯Cl1ⁱⁱ	0.82	2.44	3.194 (4)	154
N6—H6B⋯O2ⁱⁱⁱ	0.86	2.06	2.918 (4)	175
N6—H6A⋯Cl2	0.86	2.45	3.269 (4)	159
N3—H3B⋯O1^iv	0.86	2.09	2.947 (4)	175
N3—H3A⋯Cl1	0.86	2.51	3.309 (3)	156
C22—H22B⋯C17ⁱ	0.96	2.91	3.789 (7)	154
C22—H22B⋯C18ⁱ	0.96	2.71	3.575 (6)	150
C4—H4⋯Cl2^v	0.93	2.85	3.705 (4)	153
C7—H7⋯Cl1^vi	0.93	2.87	3.757 (4)	160
C13—H13⋯Cl1ⁱⁱ	0.93	2.88	3.733 (4)	152

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

Acknowledgments

The authors thank the Zhejiang Forestry University Science Foundation for financial support.

supplementary crystallographic information

Comment

Molecular structures and chemical properties of transition metal complexes of 1,8-naphthyridine (napy) and its derivatives have received much attention (Kukrek et al., 2006; Che et al., 2001) as the ligands can link to metals via several coordination modes such as monodentate, chelating bidentate, and in a dinuclear bridging fashion (Gavrilova & Bosnich, 2004). 5,7-Dimethyl-1,8-naphthyridin-2-amine is a potentially tridentate ligand and is capable of linking two to four metal atoms together to form metal aggregates (Oskui et al., 1999; Mintert & Sheldrick, 1995a; Oskui & Sheldrick, 1999; Mintert & Sheldrick, 1995b). The coordination chemistry of 5,7-dimethyl-1,8-naphthyridine-2-amine (L) has not been well studied before although a Co(II) complex (Co(L)₂Cl₂) was once described in a US patent (Bayer, 1979). As an extension of our study on naphthyridine coordination chemistry (Jin et al., 2007), herein we report the synthesis and structure of the title complex as its bis methanol solvate, (Co(L)₂(Cl)₂).2(CH₃OH).

The title compound was obtained as violet crystals by reacting cobalt chloride hexahydrate and L in methanol. The compound is air stable and light insensitive, and does not dissolve in water and most organic solvents. X-ray structural analysis shows that the complex is mononuclear, its molecular structure is shown in Fig. 1. The Co atom is positioned on an inversion center and is bonded to two L ligands and two chloride ions. Both of the two ligands coordinate to the metal center via two nitrogen atoms in a bidentate chelating fashion. The two chloride anions coordinated to the Co ion complete a very distorted octahedral geometry. With a N—Co—N bite angle of only 58.86 (11), and 60.39 (11) ° the structure can also be seen as a pseudotetrahedral complex with each of the naphthyridine ligands L counted as a singly bonded entity. The N—Co—N angle is of necessity quite small, thereby allowing for the Cl(2)—Co(1)—Cl(1) angle to expand to 96.99 (5) °. Perhaps as a result of the smaller spatial requirements of the chelating naphthyridine, the chloride ions are in cis-arrangement which is different from reported results (Harvey et al., 2004).

The two naphthyridine rings are basically planar with an r.m.s. deviation of only 0.0098, and 0.0183 ° respectively, and both ligands are almost perpendicular to each other with an angle between the root mean square planes of the two ligands of 85.4 °.

The free methanol molecules are connected to the (Co(L)₂(Cl)₂) moieties via O—H···Cl and N—H···O hydrogen bonds, and the (Co(L)₂(Cl)₂) moieties themselves are connected with each other by N—H···Cl hydrogen bonds (see Table 1). The closest C—C distance between adjacent parallel naphthyridyl rings is 3.378 (4) Å, the corresponding centroid to centroid distance for the naphthyridyl rings is 3.664 Å, which implies the presence of π-π stacking interactions between the naphthyridyl rings. Via all these interactions the compound forms a three-dimensional network structure as shown in Fig. 2.

Experimental

All reagents and solvents were used as obtained without further purification. The CHN elemental analyses were performed on a Perkin-Elmer model 2400 elemental analyzer.

To a methanol solution of cobalt chloride hexahydrate (24 mg, 0.1 mmol), was added L (17.4 mg, 0.1 mmol) in 10 ml of methanol. The solution was stirred for three minutes, then the solution was filtered. The solution was left standing at room temperature for several days, and violet crystals were isolated after slow evaporation of the methanol solution in air. Yield: 38 mg, 70.3%. Anal. Calcd for C₂₂H₃₀Cl₂CoN₆O₂: C, 48.86; H, 5.55; N, 15.55; Found: C, 48.81; H, 5.52; N, 15.49.