(Croconato-κ²O,O′)bis­(1,10-phenanthroline-κ²N,N′)manganese(II)

The title complex, [Mn(C₅O₅)(C₁₂H₈N₂)₂], lies across a crystallographic twofold axis which passes through the Mn atom and bisects the croconate ligand. The two 1,10-phenanthroline (phen) ligands are arranged in a propeller manner and the local mol­ecular geometry of the MnN₄O₂ unit is severely distorted octa­hedral. This may be inter­preted as a structural perturbation of the MnN₄ square by the croconate ligand. In the crystal structure, the dipole moments of the mol­ecules are arranged alternately along the +b and −b directions. All the phen ligands are involved in π stacking inter­actions, alternately along the [110] and [10] directions. The alternate spacings between the neighbouring phen planes in the one-dimensional π stacks are 3.361 (2) and 3.526 (2) Å.

Key indicators

• Single-crystal X-ray study
• T = 120 K
• Mean [sigma](C-C) = 0.002 Å
• R factor = 0.026
• wR factor = 0.081
• Data-to-parameter ratio = 16.0

checkCIF/PLATON results

No syntax errors found



Alert level C
PLAT062_ALERT_4_C Rescale T(min) & T(max) by .....................       1.17
PLAT094_ALERT_2_C Ratio of Maximum / Minimum Residual Density ....       2.25
PLAT164_ALERT_4_C Nr. of Refined C-H H-Atoms in Heavy-At Struct...          8
PLAT232_ALERT_2_C Hirshfeld Test Diff (M-X)  Mn1    -   O1      ..       6.37 su
PLAT232_ALERT_2_C Hirshfeld Test Diff (M-X)  Mn1    -   N1      ..       5.20 su

Alert level G
ABSTM02_ALERT_3_G  When printed, the submitted absorption T values will be
            replaced by the scaled T values. Since the ratio of scaled T's
            is identical to the ratio of reported T values, the scaling
            does not imply a change to the absorption corrections used in
            the study.
            Ratio of Tmax expected/reported      1.171
            Tmax scaled      0.873 Tmin scaled      0.722

   0 ALERT level A = In general: serious problem
   0 ALERT level B = Potentially serious problem
   5 ALERT level C = Check and explain
   1 ALERT level G = General alerts; check

   0 ALERT type 1 CIF construction/syntax error, inconsistent or missing data
   3 ALERT type 2 Indicator that the structure model may be wrong or deficient
   1 ALERT type 3 Indicator that the structure quality may be low
   2 ALERT type 4 Improvement, methodology, query or suggestion
   0 ALERT type 5 Informative message, check

---

S1. Comment

The croconate C₅O₅^2- anion has attracted increasing attention in recent years because this polydentate ligand gave rise to a variety of interesting complexes (Coronado et al., 2007; Chen et al., 2005; Maji et al., 2003; Wang et al., 2002; Sletten et al., 1998). Typically, the C₅O₅^2- anion can serve as a terminal bidentate ligand and a bridging ligand utilizing more than two O atoms for coordination. By comparison, the coordination chemistry of the neutral 1,10-phenanthroline bidentate ligand has been well studied.

Recently, we reported three mixed-ligand complexes [M(phen)₂(C₅O₅)] (M=Co, Ni, Cu) (Chen et al., 2007), which have both croconate and 1,10-phenanthroline ligands. In this study, we report a new member of this family: [Mn(phen)₂(C₅O₅)] which is isostructural to [Cu(phen)₂(C₅O₅)].

[Mn(phen)₂(C₅O₅)] shows following common features with other three known [M(phen)₂(C₅O₅)] complexes: the molecule lies across twofold axis which is along the direction of the molecular dipole moment. Around the molecular axis, two phen ligands are arranged in a chiral propeller manner. The C—O bond lengths involving coordinated O atoms are longer than those of other C—O bonds.

The mean M—N bond lengths in [M(phen)₂(C₅O₅)] series are 2.2515 (9), 2.124 (2), 2.080 (3), and 2.065 (2) Å for the Mn, Co, Ni, and Cu complexes respectively, showing monotonous shortening with increasing the atomic number. The M—O lengths in [M(phen)₂(C₅O₅)] are 2.2163 (8), 2.120 (2), 2.098 (3), and 2.303 (2) Å for the Mn, Co, Ni, and Cu complexes respectively, showing a similar shortening tendency except for Cu complex which has the longest M—O length.

The molecular conformation of [Mn(phen)₂(C₅O₅)] is close to [Cu(phen)₂(C₅O₅)] while different from [Co(phen)₂(C₅O₅)] and [Ni(phen)₂(C₅O₅)]. The dihedral angles between the two phen planes for the Mn, Co, Ni, and Cu complexes are 46.5 (1), 85.7 (1), 86.0 (1), and 40.7 (1)°, respectively. In fact, the local polyhedral CoN₄O₂ and NiN₄O₂ in [M(phen)₂(C₅O₅)] is close to the octahedral while MnN₄O₂ and CuN₄O₂ in their complexes is severely distorted from the octahedral. We can suppose that the Mn(II)(Cu(II)) ion intially combines two phen ligands forming a MnN₄ (CuN₄) square, and then this square is distorted by adding the croconato ligand. This supposition may be supported by the relatively longest Mn—O and Cu—O bond length mentioned above in these complexes.

As shown in Fig.2, the dipole moments of [Mn(phen)₂(C₅O₅)] molecules are arranged alternatively along +b and-b directions. All phen ligands are parallel packed with the π-stacks being alternatively along the [110] and [-110] directions. The spacings between the neighboring phen planes in this kind of 1-D π-stacks are 3.361 (2) and 3.526 (2) Å (alternatively spaced).

Both in the molecular view and in the crystal view, four [M(phen)₂(C₅O₅)] members can be classified into two groups: the octahedral and Pbcn symmetric isostructural pair of [Co(phen)₂(C₅O₅)] and [Ni(phen)₂(C₅O₅)]; the non-octahedral and C2/c symmetric isostructural pair of [Mn(phen)₂(C₅O₅)] and [Cu(phen)₂(C₅O₅)]. The similarity between Mn and Cu complexes here may be related to the fact that the d-shell is half-filled for Mn(II) and almost full-filled for Cu(II) ions.

Related literature

For related literature, see: Chen et al. (2005, 2007); Coronado et al. (2007); Maji et al. (2003); Sletten et al. (1998); Wang et al. (2002).

S2. Experimental

[K₂(C₅O₅)] (0.10 g) and MnCl₂.4H₂O (0.09 g) were dissolved in mixed solvent of water (15 ml) and dimethylformamide (10 ml). Then 1,10-phenanthroline (0.15 g) was added. The mixture was heated to 340–350 K under continuous stirring for 20 min and then filtered. The green prisms crystals were obtained by slow evaporation at 313 K.

S3. Refinement

All the H atoms were located in a difference Fourier map and refined in the isotropic approximation.

Computing details

Data collection: SMART (Bruker, 1997); cell refinement: SMART (Bruker, 1997); data reduction: SAINT (Bruker, 1999); program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: SHELXTL (Bruker, 1997); software used to prepare material for publication: SHELXTL (Bruker, 1997).

Figures

	Fig. 1. The molecular structure of [Mn(phen)2(C5O5)]. Displacement ellipsoids are drawn at the 30% probability level and H atoms have been omitted. [symmetry code: (i) -x, y, -z + 1/2.]
	Fig. 2. A packing plot of [Mn(phen)2(C5O5)].

(Croconato-κ²O,O')bis(1,10-phenanthroline-κ²N,N')manganese(II)

Crystal data

[Mn(C5O5)(C12H8N2)2]	F(000) = 1132
Mr = 555.40	Dx = 1.576 Mg m^−3
Monoclinic, C2/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -C 2yc	Cell parameters from 6761 reflections
a = 14.9185 (6) Å	θ = 2.4–30.0°
b = 10.3749 (4) Å	µ = 0.62 mm^−1
c = 16.0859 (6) Å	T = 120 K
β = 109.885 (1)°	Parallelepiped, green
V = 2341.30 (16) Å^3	0.44 × 0.33 × 0.22 mm
Z = 4

Data collection

Siemens SMART 1K CCD area-detector diffractometer	3356 independent reflections
Radiation source: fine-focus sealed tube	3214 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.020
Detector resolution: 8 pixels mm^-1	θmax = 30.0°, θmin = 2.4°
φ and ω scans	h = −20→20
Absorption correction: multi-scan (SADABS; Bruker, 2006)	k = −14→14
Tmin = 0.617, Tmax = 0.746	l = −22→22
16256 measured reflections

Refinement

Refinement on F^2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F^2 > 2σ(F^2)] = 0.026	Hydrogen site location: difference Fourier map
wR(F^2) = 0.081	All H-atom parameters refined
S = 1.06	w = 1/[σ^2(Fo^2) + (0.0494P)^2 + 1.5339P] where P = (Fo^2 + 2Fc^2)/3
3356 reflections	(Δ/σ)max = 0.001
210 parameters	Δρmax = 0.50 e Å^−3
0 restraints	Δρmin = −0.22 e Å^−3

Special details

Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'s involving l.s. planes.

Refinement. Refinement of F² against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F², conventional R-factors R are based on F, with F set to zero for negative F². The threshold expression of F² > σ(F²) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F² are statistically about twice as large as those based on F, and R- factors based on ALL data will be even larger.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq
Mn1	0.5000	0.26400 (2)	0.2500	0.01622 (7)
O1	0.59885 (5)	0.43062 (7)	0.28042 (5)	0.02103 (16)
O2	0.67021 (6)	0.70377 (9)	0.30364 (6)	0.02748 (18)
O3	0.5000	0.87022 (11)	0.2500	0.0219 (2)
N1	0.62594 (6)	0.15684 (8)	0.34684 (6)	0.01795 (16)
N2	0.46304 (6)	0.23245 (8)	0.37113 (6)	0.01674 (17)
C1	0.70739 (7)	0.12417 (11)	0.33554 (7)	0.0215 (2)
H1	0.7115 (10)	0.1353 (15)	0.2787 (10)	0.025 (4)*
C2	0.78638 (8)	0.07591 (11)	0.40428 (8)	0.0236 (2)
H2	0.8456 (12)	0.0555 (17)	0.3931 (11)	0.035 (4)*
C3	0.78032 (7)	0.05937 (10)	0.48675 (8)	0.0216 (2)
H3	0.8314 (10)	0.0290 (15)	0.5356 (10)	0.023 (3)*
C10	0.69459 (7)	0.09129 (10)	0.50113 (7)	0.01780 (18)
C9	0.61971 (7)	0.14089 (9)	0.42867 (6)	0.01610 (18)
C11	0.53204 (6)	0.17845 (9)	0.44123 (6)	0.01574 (18)
C12	0.52078 (7)	0.15896 (10)	0.52374 (6)	0.01709 (18)
C5	0.59808 (7)	0.10556 (10)	0.59570 (7)	0.01991 (19)
H5	0.5877 (11)	0.0922 (15)	0.6492 (11)	0.030 (4)*
C4	0.68188 (7)	0.07441 (10)	0.58486 (7)	0.02041 (19)
H4	0.7324 (11)	0.0420 (15)	0.6319 (10)	0.023 (3)*
C6	0.43206 (7)	0.19283 (10)	0.53119 (7)	0.01892 (19)
H6	0.4204 (11)	0.1750 (15)	0.5844 (11)	0.027 (4)*
C7	0.36277 (8)	0.24697 (10)	0.45998 (7)	0.0194 (2)
H7	0.3036 (12)	0.2722 (14)	0.4624 (11)	0.025 (4)*
C8	0.38134 (7)	0.26697 (10)	0.38121 (7)	0.01831 (19)
H8	0.3372 (10)	0.3074 (14)	0.3314 (10)	0.020 (3)*
C13	0.55136 (6)	0.53447 (10)	0.26577 (6)	0.01663 (18)
C14	0.58663 (7)	0.66724 (10)	0.27693 (6)	0.01791 (18)
C15	0.5000	0.75179 (14)	0.2500	0.0172 (3)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Mn1	0.01278 (11)	0.02053 (12)	0.01434 (11)	0.000	0.00330 (8)	0.000
O1	0.0128 (3)	0.0224 (4)	0.0243 (4)	0.0014 (3)	0.0017 (3)	−0.0019 (3)
O2	0.0147 (3)	0.0294 (4)	0.0350 (4)	−0.0044 (3)	0.0041 (3)	−0.0040 (3)
O3	0.0248 (5)	0.0215 (5)	0.0198 (5)	0.000	0.0083 (4)	0.000
N1	0.0156 (4)	0.0193 (4)	0.0190 (4)	0.0014 (3)	0.0061 (3)	0.0006 (3)
N2	0.0132 (4)	0.0201 (4)	0.0156 (4)	0.0011 (3)	0.0031 (3)	0.0006 (3)
C1	0.0192 (5)	0.0234 (5)	0.0236 (5)	0.0032 (4)	0.0094 (4)	0.0018 (4)
C2	0.0167 (4)	0.0249 (5)	0.0301 (5)	0.0047 (4)	0.0090 (4)	0.0017 (4)
C3	0.0147 (4)	0.0218 (5)	0.0256 (5)	0.0033 (3)	0.0034 (4)	0.0011 (4)
C10	0.0144 (4)	0.0173 (4)	0.0193 (4)	0.0003 (3)	0.0025 (3)	−0.0004 (3)
C9	0.0136 (4)	0.0160 (4)	0.0175 (4)	−0.0001 (3)	0.0037 (3)	−0.0007 (3)
C11	0.0130 (4)	0.0167 (4)	0.0160 (4)	−0.0004 (3)	0.0030 (3)	−0.0010 (3)
C12	0.0155 (4)	0.0186 (4)	0.0155 (4)	−0.0010 (3)	0.0032 (3)	−0.0021 (3)
C5	0.0198 (4)	0.0228 (5)	0.0147 (4)	0.0001 (4)	0.0027 (3)	−0.0005 (3)
C4	0.0174 (4)	0.0219 (5)	0.0176 (4)	0.0012 (3)	0.0003 (3)	0.0003 (3)
C6	0.0179 (4)	0.0228 (5)	0.0161 (4)	−0.0019 (4)	0.0060 (3)	−0.0030 (4)
C7	0.0150 (4)	0.0239 (5)	0.0196 (5)	0.0005 (3)	0.0064 (4)	−0.0022 (3)
C8	0.0138 (4)	0.0220 (5)	0.0181 (5)	0.0012 (3)	0.0040 (3)	0.0002 (3)
C13	0.0119 (4)	0.0230 (4)	0.0134 (4)	−0.0001 (3)	0.0023 (3)	−0.0011 (3)
C14	0.0139 (4)	0.0232 (5)	0.0157 (4)	−0.0009 (3)	0.0040 (3)	−0.0018 (3)
C15	0.0150 (6)	0.0234 (6)	0.0130 (6)	0.000	0.0046 (5)	0.000

Geometric parameters (Å, º)

Mn1—O1	2.2163 (8)	C10—C9	1.4091 (13)
Mn1—O1^i	2.2163 (8)	C10—C4	1.4333 (15)
Mn1—N2	2.2222 (9)	C9—C11	1.4433 (13)
Mn1—N2^i	2.2222 (9)	C11—C12	1.4080 (13)
Mn1—N1^i	2.2807 (9)	C12—C6	1.4134 (13)
Mn1—N1	2.2807 (9)	C12—C5	1.4383 (13)
O1—C13	1.2668 (12)	C5—C4	1.3587 (15)
O2—C14	1.2323 (12)	C5—H5	0.934 (17)
O3—C15	1.2287 (18)	C4—H4	0.931 (15)
N1—C1	1.3322 (13)	C6—C7	1.3750 (15)
N1—C9	1.3607 (13)	C6—H6	0.947 (16)
N2—C8	1.3321 (13)	C7—C8	1.4015 (15)
N2—C11	1.3621 (12)	C7—H7	0.934 (17)
C1—C2	1.4055 (15)	C8—H8	0.945 (14)
C1—H1	0.944 (16)	C13—C13^i	1.4412 (18)
C2—C3	1.3709 (16)	C13—C14	1.4637 (14)
C2—H2	0.982 (17)	C14—C15	1.4989 (13)
C3—C10	1.4143 (14)	C15—C14^i	1.4989 (13)
C3—H3	0.943 (15)
O1—Mn1—O1^i	77.48 (4)	N1—C9—C10	123.29 (9)
O1—Mn1—N2	105.44 (3)	N1—C9—C11	117.77 (8)
O1^i—Mn1—N2	87.91 (3)	C10—C9—C11	118.94 (9)
O1—Mn1—N2^i	87.91 (3)	N2—C11—C12	122.72 (9)
O1^i—Mn1—N2^i	105.44 (3)	N2—C11—C9	117.44 (9)
N2—Mn1—N2^i	163.06 (5)	C12—C11—C9	119.84 (8)
O1—Mn1—N1^i	149.62 (3)	C11—C12—C6	117.37 (9)
O1^i—Mn1—N1^i	84.13 (3)	C11—C12—C5	119.60 (9)
N2—Mn1—N1^i	97.74 (3)	C6—C12—C5	123.03 (9)
N2^i—Mn1—N1^i	73.85 (3)	C4—C5—C12	120.61 (9)
O1—Mn1—N1	84.13 (3)	C4—C5—H5	122.0 (10)
O1^i—Mn1—N1	149.62 (3)	C12—C5—H5	117.3 (10)
N2—Mn1—N1	73.85 (3)	C5—C4—C10	120.87 (9)
N2^i—Mn1—N1	97.74 (3)	C5—C4—H4	120.5 (9)
N1^i—Mn1—N1	121.66 (5)	C10—C4—H4	118.6 (9)
C13—O1—Mn1	109.53 (6)	C7—C6—C12	119.42 (9)
C1—N1—C9	117.82 (9)	C7—C6—H6	121.0 (9)
C1—N1—Mn1	127.48 (7)	C12—C6—H6	119.5 (9)
C9—N1—Mn1	114.11 (6)	C6—C7—C8	119.34 (10)
C8—N2—C11	118.35 (9)	C6—C7—H7	122.2 (10)
C8—N2—Mn1	125.26 (7)	C8—C7—H7	118.5 (10)
C11—N2—Mn1	116.32 (7)	N2—C8—C7	122.73 (10)
N1—C1—C2	122.87 (10)	N2—C8—H8	114.7 (9)
N1—C1—H1	117.6 (9)	C7—C8—H8	122.5 (9)
C2—C1—H1	119.5 (9)	O1—C13—C13^i	121.73 (5)
C3—C2—C1	119.50 (10)	O1—C13—C14	128.51 (8)
C3—C2—H2	120.6 (10)	C13^i—C13—C14	109.76 (5)
C1—C2—H2	119.9 (10)	O2—C14—C13	127.67 (10)
C2—C3—C10	119.33 (9)	O2—C14—C15	126.27 (10)
C2—C3—H3	123.1 (9)	C13—C14—C15	106.06 (8)
C10—C3—H3	117.5 (9)	O3—C15—C14^i	125.82 (6)
C9—C10—C3	117.18 (9)	O3—C15—C14	125.82 (6)
C9—C10—C4	120.06 (9)	C14^i—C15—C14	108.36 (12)
C3—C10—C4	122.76 (9)

Symmetry code: (i) −x+1, y, −z+1/2.