The title compound, [Cd2(SO3)2(C18H12N6)2]·8H2O, is a dimer built up around a symmetry center, where the sulfite anion displays a so far unreported coordination mode in metal-organic complexes; the anion binds as a μ2-sulfite-κ4O,O′:O′,O′′ ligand to two symmetry-related seven-coordinate CdII cations, binding through its three O atoms by way of two chelate bites with an O atom in common, which acts as a bridge. The cation coordination is completed by a 2,4,6-tri-2-pyridyl-1,3,5-triazine ligand acting in its usual tridentate mode.
Supporting information
CCDC reference: 609402
2,4,6-Tris(2-pyridyl)-1,3,5-triazine and Cd acetate were dissolved in 95% ethanol and left to diffuse over an aqueous solution of potassium pyrosulfite. The Metal–tpt–K2S2O5 molar ratio was 1:1:2. After five months, irregular colorless crystals suitable for X-ray analysis were obtained.
Hydrogen atoms attached to carbon were included at their calculated positions with d(C—H), 0.93 Å and allowed to ride both in position as in their CH Isotropic displacement parameters (Uisot(H) = 1.2*Ueq(C)). Those attached to water molecules were found in the difference Fourier synthesis and refined with restrained O—H:0.82 (1) Å, H···H:1.30 (2) Å, but free Uisot(H).
Data collection: SMART-NT (Bruker, 2001); cell refinement: SAINT-NT (Bruker, 2000); data reduction: SAINT-NT; program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: SHELXTL-NT (Sheldrick, 2000); software used to prepare material for publication: SHELXTL-NT and PLATON (Spek, 2005).
Di-µ
2-sulfito-
κ4O,
O':
κ4O',
O''-[2,4,6-tris(2-pyridyl)- 1,3,5-triazine-
κ3N2,
N1,
N6]cadmium(II) octahydrate
top
Crystal data top
[Cd2(SO3)2(C18H12N6)2]·8H2O | V = 1085.0 (3) Å3 |
Mr = 1153.72 | Z = 1 |
Triclinic, P1 | F(000) = 580 |
Hall symbol: -P 1 | Dx = 1.766 Mg m−3 |
a = 8.5826 (12) Å | Mo Kα radiation, λ = 0.71073 Å |
b = 10.5117 (14) Å | µ = 1.16 mm−1 |
c = 13.1078 (17) Å | T = 295 K |
α = 103.902 (2)° | Blocks, colorless |
β = 107.988 (2)° | 0.26 × 0.18 × 0.12 mm |
γ = 91.639 (2)° | |
Data collection top
Bruker SMART CCD area-detector diffractometer | 4665 independent reflections |
Radiation source: fine-focus sealed tube | 4289 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.019 |
ϕ and ω scans | θmax = 28.0°, θmin = 1.7° |
Absorption correction: multi-scan (SADABS; Sheldrick, 2001) | h = −11→11 |
Tmin = 0.74, Tmax = 0.88 | k = −13→13 |
9107 measured reflections | l = −16→17 |
Refinement top
Refinement on F2 | Primary atom site location: structure-invariant direct methods |
Least-squares matrix: full | Secondary atom site location: difference Fourier map |
R[F2 > 2σ(F2)] = 0.033 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.088 | H atoms treated by a mixture of independent and constrained refinement |
S = 0.84 | w = 1/[σ2(Fo2) + (0.0703P)2 + 0.6306P] where P = (Fo2 + 2Fc2)/3 |
4665 reflections | (Δ/σ)max = 0.002 |
331 parameters | Δρmax = 1.13 e Å−3 |
12 restraints | Δρmin = −0.38 e Å−3 |
Crystal data top
[Cd2(SO3)2(C18H12N6)2]·8H2O | γ = 91.639 (2)° |
Mr = 1153.72 | V = 1085.0 (3) Å3 |
Triclinic, P1 | Z = 1 |
a = 8.5826 (12) Å | Mo Kα radiation |
b = 10.5117 (14) Å | µ = 1.16 mm−1 |
c = 13.1078 (17) Å | T = 295 K |
α = 103.902 (2)° | 0.26 × 0.18 × 0.12 mm |
β = 107.988 (2)° | |
Data collection top
Bruker SMART CCD area-detector diffractometer | 4665 independent reflections |
Absorption correction: multi-scan (SADABS; Sheldrick, 2001) | 4289 reflections with I > 2σ(I) |
Tmin = 0.74, Tmax = 0.88 | Rint = 0.019 |
9107 measured reflections | |
Refinement top
R[F2 > 2σ(F2)] = 0.033 | 12 restraints |
wR(F2) = 0.088 | H atoms treated by a mixture of independent and constrained refinement |
S = 0.84 | Δρmax = 1.13 e Å−3 |
4665 reflections | Δρmin = −0.38 e Å−3 |
331 parameters | |
Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top | x | y | z | Uiso*/Ueq | |
Cd1 | 0.51459 (2) | 0.596554 (17) | 0.641740 (14) | 0.03450 (8) | |
S1 | 0.69658 (9) | 0.36093 (7) | 0.57426 (5) | 0.03723 (15) | |
O1 | 0.7434 (3) | 0.3759 (2) | 0.47503 (17) | 0.0477 (5) | |
O2 | 0.7513 (2) | 0.4936 (2) | 0.66154 (16) | 0.0440 (5) | |
O3 | 0.5088 (2) | 0.3598 (2) | 0.53321 (16) | 0.0432 (4) | |
N1 | 0.6839 (3) | 0.8109 (2) | 0.71068 (18) | 0.0369 (5) | |
N2 | 0.5413 (3) | 0.7031 (2) | 0.82694 (17) | 0.0347 (5) | |
N3 | 0.3430 (3) | 0.4824 (2) | 0.71436 (18) | 0.0362 (5) | |
N4 | 0.4820 (3) | 0.7009 (2) | 0.98974 (18) | 0.0371 (5) | |
N5 | 0.6551 (3) | 0.8803 (2) | 0.98680 (19) | 0.0384 (5) | |
N6 | 0.6872 (3) | 0.9952 (3) | 1.2021 (2) | 0.0464 (6) | |
C1 | 0.7557 (4) | 0.8613 (3) | 0.6501 (2) | 0.0429 (6) | |
H1B | 0.7319 | 0.8178 | 0.5755 | 0.051* | |
C2 | 0.8636 (4) | 0.9750 (3) | 0.6936 (3) | 0.0499 (7) | |
H2A | 0.9113 | 1.0072 | 0.6487 | 0.060* | |
C3 | 0.9001 (4) | 1.0403 (3) | 0.8032 (3) | 0.0520 (8) | |
H3A | 0.9747 | 1.1161 | 0.8342 | 0.062* | |
C4 | 0.8243 (4) | 0.9918 (3) | 0.8671 (2) | 0.0437 (6) | |
H4B | 0.8440 | 1.0357 | 0.9413 | 0.052* | |
C5 | 0.7187 (3) | 0.8768 (3) | 0.8181 (2) | 0.0348 (5) | |
C6 | 0.6347 (3) | 0.8171 (3) | 0.8818 (2) | 0.0339 (5) | |
C7 | 0.5751 (3) | 0.8164 (3) | 1.0366 (2) | 0.0350 (5) | |
C8 | 0.4653 (3) | 0.6493 (3) | 0.8837 (2) | 0.0338 (5) | |
C9 | 0.3518 (3) | 0.5281 (3) | 0.8207 (2) | 0.0338 (5) | |
C10 | 0.2536 (4) | 0.4707 (3) | 0.8676 (3) | 0.0433 (6) | |
H10A | 0.2650 | 0.5020 | 0.9424 | 0.052* | |
C11 | 0.1387 (4) | 0.3657 (3) | 0.8002 (3) | 0.0491 (7) | |
H11A | 0.0700 | 0.3256 | 0.8288 | 0.059* | |
C12 | 0.1266 (4) | 0.3211 (3) | 0.6902 (3) | 0.0473 (7) | |
H12A | 0.0486 | 0.2513 | 0.6433 | 0.057* | |
C13 | 0.2316 (4) | 0.3812 (3) | 0.6505 (2) | 0.0428 (6) | |
H13A | 0.2244 | 0.3497 | 0.5764 | 0.051* | |
C14 | 0.5919 (3) | 0.8798 (3) | 1.1547 (2) | 0.0363 (6) | |
C15 | 0.5113 (4) | 0.8197 (3) | 1.2102 (2) | 0.0443 (6) | |
H15A | 0.4450 | 0.7400 | 1.1744 | 0.053* | |
C16 | 0.5315 (4) | 0.8808 (3) | 1.3198 (3) | 0.0501 (7) | |
H16A | 0.4796 | 0.8424 | 1.3594 | 0.060* | |
C17 | 0.6287 (4) | 0.9984 (3) | 1.3695 (2) | 0.0511 (8) | |
H17A | 0.6446 | 1.0412 | 1.4434 | 0.061* | |
C18 | 0.7029 (5) | 1.0524 (3) | 1.3075 (3) | 0.0536 (8) | |
H18A | 0.7675 | 1.1332 | 1.3413 | 0.064* | |
O1W | 1.1519 (4) | 0.7983 (3) | 0.8610 (2) | 0.0656 (7) | |
H1WA | 1.108 (5) | 0.754 (3) | 0.7968 (14) | 0.066 (13)* | |
H1WB | 1.195 (5) | 0.870 (2) | 0.863 (3) | 0.076 (14)* | |
O2W | 0.7897 (4) | 0.4772 (3) | 0.8799 (2) | 0.0662 (7) | |
H2WA | 0.859 (6) | 0.541 (4) | 0.912 (3) | 0.13 (2)* | |
H2WB | 0.773 (5) | 0.458 (4) | 0.8130 (10) | 0.082 (14)* | |
O3W | 1.0118 (3) | 0.6592 (3) | 0.6336 (3) | 0.0638 (6) | |
H3WA | 0.950 (5) | 0.603 (3) | 0.641 (4) | 0.097 (18)* | |
H3WB | 1.065 (5) | 0.625 (4) | 0.594 (3) | 0.077 (14)* | |
O4W | 1.0274 (4) | 0.6911 (3) | 1.0013 (2) | 0.0685 (7) | |
H4WA | 1.065 (4) | 0.715 (4) | 0.958 (3) | 0.062 (12)* | |
H4WB | 1.094 (5) | 0.654 (7) | 1.040 (5) | 0.16 (3)* | |
Atomic displacement parameters (Å2) top | U11 | U22 | U33 | U12 | U13 | U23 |
Cd1 | 0.04067 (13) | 0.03593 (12) | 0.02733 (12) | −0.00239 (8) | 0.01467 (8) | 0.00512 (8) |
S1 | 0.0434 (4) | 0.0376 (3) | 0.0325 (3) | 0.0032 (3) | 0.0139 (3) | 0.0105 (3) |
O1 | 0.0474 (11) | 0.0636 (13) | 0.0390 (10) | 0.0083 (10) | 0.0236 (9) | 0.0135 (10) |
O2 | 0.0437 (11) | 0.0468 (11) | 0.0343 (10) | −0.0007 (9) | 0.0089 (8) | 0.0029 (8) |
O3 | 0.0408 (10) | 0.0505 (11) | 0.0384 (10) | −0.0059 (9) | 0.0147 (8) | 0.0106 (9) |
N1 | 0.0435 (12) | 0.0362 (11) | 0.0332 (11) | 0.0001 (9) | 0.0170 (10) | 0.0073 (9) |
N2 | 0.0424 (12) | 0.0332 (11) | 0.0301 (11) | −0.0010 (9) | 0.0161 (9) | 0.0061 (9) |
N3 | 0.0411 (12) | 0.0372 (11) | 0.0317 (11) | −0.0004 (9) | 0.0147 (9) | 0.0081 (9) |
N4 | 0.0445 (12) | 0.0375 (11) | 0.0313 (11) | 0.0008 (10) | 0.0156 (10) | 0.0084 (9) |
N5 | 0.0459 (13) | 0.0358 (11) | 0.0330 (11) | −0.0018 (10) | 0.0162 (10) | 0.0048 (9) |
N6 | 0.0580 (15) | 0.0458 (13) | 0.0333 (12) | −0.0039 (12) | 0.0187 (11) | 0.0027 (10) |
C1 | 0.0519 (16) | 0.0437 (15) | 0.0374 (14) | −0.0006 (13) | 0.0229 (13) | 0.0081 (12) |
C2 | 0.0607 (19) | 0.0467 (16) | 0.0522 (17) | −0.0035 (14) | 0.0317 (15) | 0.0150 (14) |
C3 | 0.0588 (19) | 0.0415 (15) | 0.0556 (18) | −0.0137 (14) | 0.0242 (15) | 0.0077 (14) |
C4 | 0.0515 (17) | 0.0380 (14) | 0.0388 (15) | −0.0049 (12) | 0.0182 (13) | 0.0016 (12) |
C5 | 0.0380 (13) | 0.0333 (12) | 0.0349 (13) | 0.0014 (10) | 0.0155 (11) | 0.0076 (10) |
C6 | 0.0373 (13) | 0.0349 (12) | 0.0289 (12) | 0.0031 (10) | 0.0115 (10) | 0.0066 (10) |
C7 | 0.0398 (14) | 0.0372 (13) | 0.0290 (12) | 0.0058 (11) | 0.0120 (10) | 0.0091 (10) |
C8 | 0.0382 (13) | 0.0344 (12) | 0.0313 (12) | 0.0038 (10) | 0.0145 (11) | 0.0093 (10) |
C9 | 0.0389 (13) | 0.0328 (12) | 0.0332 (12) | 0.0034 (10) | 0.0163 (11) | 0.0094 (10) |
C10 | 0.0536 (17) | 0.0418 (14) | 0.0434 (15) | 0.0009 (13) | 0.0277 (13) | 0.0124 (12) |
C11 | 0.0532 (17) | 0.0414 (15) | 0.0618 (19) | −0.0016 (13) | 0.0325 (15) | 0.0133 (14) |
C12 | 0.0429 (15) | 0.0399 (14) | 0.0550 (18) | −0.0036 (12) | 0.0157 (14) | 0.0060 (13) |
C13 | 0.0477 (16) | 0.0398 (14) | 0.0371 (14) | −0.0033 (12) | 0.0131 (12) | 0.0048 (11) |
C14 | 0.0417 (14) | 0.0387 (13) | 0.0296 (12) | 0.0072 (11) | 0.0139 (11) | 0.0074 (11) |
C15 | 0.0545 (17) | 0.0434 (15) | 0.0387 (14) | 0.0026 (13) | 0.0209 (13) | 0.0104 (12) |
C16 | 0.067 (2) | 0.0521 (17) | 0.0407 (16) | 0.0077 (15) | 0.0285 (15) | 0.0148 (13) |
C17 | 0.072 (2) | 0.0526 (17) | 0.0322 (14) | 0.0117 (16) | 0.0242 (14) | 0.0081 (13) |
C18 | 0.068 (2) | 0.0468 (17) | 0.0394 (16) | −0.0073 (15) | 0.0189 (15) | −0.0018 (13) |
O1W | 0.0848 (19) | 0.0587 (15) | 0.0609 (17) | 0.0043 (14) | 0.0258 (15) | 0.0276 (13) |
O2W | 0.0746 (18) | 0.085 (2) | 0.0417 (13) | −0.0008 (15) | 0.0244 (13) | 0.0165 (13) |
O3W | 0.0599 (15) | 0.0549 (14) | 0.0780 (18) | −0.0028 (12) | 0.0353 (14) | 0.0043 (13) |
O4W | 0.099 (2) | 0.0547 (15) | 0.0590 (16) | 0.0002 (14) | 0.0379 (16) | 0.0132 (13) |
Geometric parameters (Å, º) top
Cd1—O1i | 2.342 (2) | C4—H4B | 0.9300 |
Cd1—O2 | 2.302 (2) | C5—C6 | 1.486 (4) |
Cd1—O3 | 2.543 (2) | C7—C14 | 1.491 (4) |
Cd1—O3i | 2.395 (2) | C8—C9 | 1.477 (4) |
Cd1—N1 | 2.455 (2) | C9—C10 | 1.386 (4) |
Cd1—N2 | 2.353 (2) | C10—C11 | 1.379 (4) |
Cd1—N3 | 2.414 (2) | C10—H10A | 0.9300 |
S1—O1 | 1.515 (2) | C11—C12 | 1.374 (5) |
S1—O2 | 1.529 (2) | C11—H11A | 0.9300 |
S1—O3 | 1.532 (2) | C12—C13 | 1.378 (4) |
N1—C1 | 1.332 (4) | C12—H12A | 0.9300 |
N1—C5 | 1.346 (3) | C13—H13A | 0.9300 |
N2—C6 | 1.331 (3) | C14—C15 | 1.383 (4) |
N2—C8 | 1.334 (3) | C15—C16 | 1.379 (4) |
N3—C13 | 1.329 (4) | C15—H15A | 0.9300 |
N3—C9 | 1.338 (3) | C16—C17 | 1.366 (5) |
N4—C8 | 1.325 (3) | C16—H16A | 0.9300 |
N4—C7 | 1.331 (4) | C17—C18 | 1.382 (5) |
N5—C6 | 1.331 (3) | C17—H17A | 0.9300 |
N5—C7 | 1.345 (4) | C18—H18A | 0.9300 |
N6—C18 | 1.330 (4) | O1W—H1WA | 0.82 (2) |
N6—C14 | 1.339 (4) | O1W—H1WB | 0.82 (3) |
C1—C2 | 1.377 (4) | O2W—H2WA | 0.82 (5) |
C1—H1B | 0.9300 | O2W—H2WB | 0.82 (2) |
C2—C3 | 1.367 (5) | O3W—H3WA | 0.83 (4) |
C2—H2A | 0.9300 | O3W—H3WB | 0.82 (4) |
C3—C4 | 1.381 (4) | O4W—H4WA | 0.81 (4) |
C3—H3A | 0.9300 | O4W—H4WB | 0.82 (5) |
C4—C5 | 1.379 (4) | | |
| | | |
O2—Cd1—O1i | 148.00 (7) | C3—C2—H2A | 120.3 |
O2—Cd1—N2 | 102.30 (7) | C1—C2—H2A | 120.3 |
O1i—Cd1—N2 | 109.26 (8) | C2—C3—C4 | 118.9 (3) |
O2—Cd1—O3i | 97.32 (7) | C2—C3—H3A | 120.5 |
O1i—Cd1—O3i | 60.25 (7) | C4—C3—H3A | 120.5 |
N2—Cd1—O3i | 141.88 (7) | C5—C4—C3 | 118.3 (3) |
O2—Cd1—N3 | 106.51 (8) | C5—C4—H4B | 120.9 |
O1i—Cd1—N3 | 81.46 (7) | C3—C4—H4B | 120.9 |
N2—Cd1—N3 | 67.59 (7) | N1—C5—C4 | 123.2 (2) |
O3i—Cd1—N3 | 136.23 (7) | N1—C5—C6 | 115.3 (2) |
O2—Cd1—N1 | 89.26 (7) | C4—C5—C6 | 121.5 (2) |
O1i—Cd1—N1 | 107.68 (8) | N5—C6—N2 | 124.9 (2) |
N2—Cd1—N1 | 66.77 (7) | N5—C6—C5 | 119.0 (2) |
O3i—Cd1—N1 | 81.29 (7) | N2—C6—C5 | 116.1 (2) |
N3—Cd1—N1 | 133.89 (7) | N4—C7—N5 | 125.8 (2) |
O2—Cd1—O3 | 58.63 (7) | N4—C7—C14 | 116.8 (2) |
O1i—Cd1—O3 | 93.89 (7) | N5—C7—C14 | 117.4 (2) |
N2—Cd1—O3 | 135.42 (7) | N4—C8—N2 | 123.9 (2) |
O3i—Cd1—O3 | 82.66 (7) | N4—C8—C9 | 119.8 (2) |
N3—Cd1—O3 | 79.44 (7) | N2—C8—C9 | 116.3 (2) |
N1—Cd1—O3 | 141.63 (7) | N3—C9—C10 | 122.5 (3) |
O2—Cd1—S1i | 123.66 (5) | N3—C9—C8 | 115.8 (2) |
O1i—Cd1—S1i | 29.88 (5) | C10—C9—C8 | 121.6 (2) |
N2—Cd1—S1i | 131.50 (6) | C11—C10—C9 | 118.2 (3) |
O3i—Cd1—S1i | 30.48 (5) | C11—C10—H10A | 120.9 |
N3—Cd1—S1i | 108.36 (6) | C9—C10—H10A | 120.9 |
N1—Cd1—S1i | 96.83 (6) | C12—C11—C10 | 119.3 (3) |
O3—Cd1—S1i | 86.26 (5) | C12—C11—H11A | 120.3 |
O1—S1—O2 | 106.54 (12) | C10—C11—H11A | 120.3 |
O1—S1—O3 | 102.60 (12) | C11—C12—C13 | 119.0 (3) |
O2—S1—O3 | 102.16 (12) | C11—C12—H12A | 120.5 |
O1—S1—Cd1i | 50.36 (8) | C13—C12—H12A | 120.5 |
O2—S1—Cd1i | 109.41 (8) | N3—C13—C12 | 122.4 (3) |
O3—S1—Cd1i | 52.46 (8) | N3—C13—H13A | 118.8 |
S1—O1—Cd1i | 99.76 (10) | C12—C13—H13A | 118.8 |
S1—O2—Cd1 | 104.31 (10) | N6—C14—C15 | 123.0 (3) |
S1—O3—Cd1i | 97.06 (9) | N6—C14—C7 | 116.7 (2) |
S1—O3—Cd1 | 94.14 (9) | C15—C14—C7 | 120.2 (3) |
Cd1i—O3—Cd1 | 97.34 (7) | C16—C15—C14 | 118.4 (3) |
C1—N1—C5 | 117.4 (2) | C16—C15—H15A | 120.8 |
C1—N1—Cd1 | 123.55 (18) | C14—C15—H15A | 120.8 |
C5—N1—Cd1 | 118.77 (17) | C17—C16—C15 | 119.3 (3) |
C6—N2—C8 | 116.3 (2) | C17—C16—H16A | 120.4 |
C6—N2—Cd1 | 122.73 (17) | C15—C16—H16A | 120.4 |
C8—N2—Cd1 | 120.96 (17) | C16—C17—C18 | 118.5 (3) |
C13—N3—C9 | 118.6 (2) | C16—C17—H17A | 120.7 |
C13—N3—Cd1 | 122.27 (18) | C18—C17—H17A | 120.7 |
C9—N3—Cd1 | 119.00 (17) | N6—C18—C17 | 123.6 (3) |
C8—N4—C7 | 115.3 (2) | N6—C18—H18A | 118.2 |
C6—N5—C7 | 113.8 (2) | C17—C18—H18A | 118.2 |
C18—N6—C14 | 117.2 (3) | H1WA—O1W—H1WB | 111 (4) |
N1—C1—C2 | 122.7 (3) | H2WA—O2W—H2WB | 111 (4) |
N1—C1—H1B | 118.6 | H3WA—O3W—H3WB | 110 (4) |
C2—C1—H1B | 118.6 | H4WA—O4W—H4WB | 111 (4) |
C3—C2—C1 | 119.5 (3) | | |
Symmetry code: (i) −x+1, −y+1, −z+1. |
Hydrogen-bond geometry (Å, º) top
D—H···A | D—H | H···A | D···A | D—H···A |
O1W—H1WA···O3W | 0.82 (2) | 2.02 (2) | 2.838 (4) | 174 (3) |
O1W—H1WB···N6ii | 0.82 (3) | 2.19 (3) | 2.950 (4) | 154 (4) |
O2W—H2WA···O4W | 0.82 (5) | 1.97 (4) | 2.785 (4) | 175 (5) |
O2W—H2WB···O2 | 0.82 (2) | 2.06 (2) | 2.827 (3) | 156 (4) |
O3W—H3WA···O2 | 0.83 (4) | 2.15 (4) | 2.958 (3) | 166 (4) |
O3W—H3WB···O1iii | 0.82 (4) | 2.11 (4) | 2.867 (3) | 154 (4) |
O4W—H4WA···O1W | 0.82 (4) | 2.01 (4) | 2.817 (4) | 173 (4) |
O4W—H4WB···O2Wiv | 0.82 (5) | 2.03 (5) | 2.827 (5) | 165 (7) |
Symmetry codes: (ii) −x+2, −y+2, −z+2; (iii) −x+2, −y+1, −z+1; (iv) −x+2, −y+1, −z+2. |
Experimental details
Crystal data |
Chemical formula | [Cd2(SO3)2(C18H12N6)2]·8H2O |
Mr | 1153.72 |
Crystal system, space group | Triclinic, P1 |
Temperature (K) | 295 |
a, b, c (Å) | 8.5826 (12), 10.5117 (14), 13.1078 (17) |
α, β, γ (°) | 103.902 (2), 107.988 (2), 91.639 (2) |
V (Å3) | 1085.0 (3) |
Z | 1 |
Radiation type | Mo Kα |
µ (mm−1) | 1.16 |
Crystal size (mm) | 0.26 × 0.18 × 0.12 |
|
Data collection |
Diffractometer | Bruker SMART CCD area-detector diffractometer |
Absorption correction | Multi-scan (SADABS; Sheldrick, 2001) |
Tmin, Tmax | 0.74, 0.88 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 9107, 4665, 4289 |
Rint | 0.019 |
(sin θ/λ)max (Å−1) | 0.660 |
|
Refinement |
R[F2 > 2σ(F2)], wR(F2), S | 0.033, 0.088, 0.84 |
No. of reflections | 4665 |
No. of parameters | 331 |
No. of restraints | 12 |
H-atom treatment | H atoms treated by a mixture of independent and constrained refinement |
Δρmax, Δρmin (e Å−3) | 1.13, −0.38 |
Selected geometric parameters (Å, º) topCd1—O1i | 2.342 (2) | Cd1—N2 | 2.353 (2) |
Cd1—O2 | 2.302 (2) | Cd1—N3 | 2.414 (2) |
Cd1—O3 | 2.543 (2) | S1—O1 | 1.515 (2) |
Cd1—O3i | 2.395 (2) | S1—O2 | 1.529 (2) |
Cd1—N1 | 2.455 (2) | S1—O3 | 1.532 (2) |
| | | |
O1—S1—O2 | 106.54 (12) | O2—S1—O3 | 102.16 (12) |
O1—S1—O3 | 102.60 (12) | | |
Symmetry code: (i) −x+1, −y+1, −z+1. |
Hydrogen-bond geometry (Å, º) top
D—H···A | D—H | H···A | D···A | D—H···A |
O1W—H1WA···O3W | 0.82 (2) | 2.02 (2) | 2.838 (4) | 174 (3) |
O1W—H1WB···N6ii | 0.82 (3) | 2.19 (3) | 2.950 (4) | 154 (4) |
O2W—H2WA···O4W | 0.82 (5) | 1.97 (4) | 2.785 (4) | 175 (5) |
O2W—H2WB···O2 | 0.82 (2) | 2.06 (2) | 2.827 (3) | 156 (4) |
O3W—H3WA···O2 | 0.83 (4) | 2.15 (4) | 2.958 (3) | 166 (4) |
O3W—H3WB···O1iii | 0.82 (4) | 2.11 (4) | 2.867 (3) | 154 (4) |
O4W—H4WA···O1W | 0.82 (4) | 2.01 (4) | 2.817 (4) | 173 (4) |
O4W—H4WB···O2Wiv | 0.82 (5) | 2.03 (5) | 2.827 (5) | 165 (7) |
Symmetry codes: (ii) −x+2, −y+2, −z+2; (iii) −x+2, −y+1, −z+1; (iv) −x+2, −y+1, −z+2. |
π···π contacts (Å, °) in (1). topCg···Cg | ccd | sa | ipd |
Cg1···Cg4v | 3.720 (2) | 19.54 (2) | 3.506 (2) |
Cg3···Cg4vi | 4.035 (2) | 36.66 (2) | 3.237 (2) |
Symmetry codes: (v) 1 − x, 2 − y, 2 − z, (vi) 1 − x, 1 − y, 2 − z. ccd: center-to-center distance. sa: (mean) slippage angle. ipd: (mean) interplanar distance.
Cg1: N1,C1->C5. Cg3: N3,C9->C13. Cg4: N4,C14->C18. |
The sulfite anion has proved to be a very versatile ligand, both in sulfite salts, where it displays an amazingly complex diversity of coordination modes, and in coordination compounds with organic ligands, where the variety is not so ample but still important. A search of the November 2005 release of the Cambridge Structural Database (CSD; Allen, 2002) shows eight different coordination modes for the anion, presented in the first scheme below. When attached to a single cation the ligand appears to bind through S in a µ-κS mode (Type 1), through one O atom (Type 2) or through two O atoms in a µ-κ2 O,O' mode (Type 3). When two different cationic sites are involved, the anion binds in three alternative modes, viz. via its S and one O atom, as µ2-κ2 S:O (Type 4), through two O atoms, as µ2-κ2O:O' (Type 5), or with its three O atoms, in a µ2-κ3O,O':O" mode (Type 6). Finally, when binding to three cations, it always does so via its three O atoms, either as a µ3-κ2 O:O':O' mode (Type 7) or a µ3-κ3O:O':O" mode (Type 8). Type 1 compounds are the most common (29 entries in the CSD, mostly CoIII complexes). The geometry of the sulfite unit in this type of coordination is quite regular, with all angles around 110° and S—O distances not significantly different [mean value 1.467 (2) Å] except in the case when the O atom is involved in hydorgen bonds, which seems to lengthen the S—O bonds [mean value 1.474 (6) Å; CSD refcodes STEDCOI10, VEBJAN, VEBJER, VEBJIV and XUFVEZ). The mean S—O bond length is considerably shorter than those in ionic sulfite salts [1.529 (7) Å (Battelle & Trueblood, 1965) and 1.536 (7) Å (Baggio & Becka, 1969)]. In other cases when O atoms are involved in coordination, S—O bonds show a characteristic lengthening for S—Ocoord as compared with S—Onon-coord ones. This effect can be seen in the following cases, referred to by their CSD reference codes (mean distances are mentioned as S—Ocoord/S—Onon-coord): BERXUR [Type 2, 1.591 (1)/1.504 (1) Å]; AVAZAY, FIFBAX, KIRBOC and YAPMOR [Type 3, 1.545 (17)/1.364 (16) Å]; FEYNUS, KAJCON, LAMBIK, LOQCAV, SOQXUR, YIQFOT and YIQFUZ [Type 4, 1.519 (2)/1.460 (3) Å]; and ALELUY, KAVJIA and ZETXEB [Type 5, 1.548 (3)/1.489 (1) Å]. Angles are quite regular, all around the expected tetrahedral values, except in the case of the constraints introduced by chelation, leading to angles as small as 90° (FIFBAX and YAPMOR) or 98° (IHIWOL and GAKTES, Type 6). There are only two entries showing an O atom acting as a bridge between two metal centres (Type 7, GAKTIW and HOFCEK). In these cases, the S—Obridge bond length [mean value 1.563 (1) Å] is considerably longer than the other S—O bonds [S—Onon-coord = 1.507 (2) Å and S—Ocoord = 1.521 (1) Å].
The title complex, (I), is a dimer built up around a symmetry center (Fig. 1), with two symmetry-related seven-coordinate CdII cations bound to a tridentate 2,4,6-tris(2-pyridyl)-1,3,5-triazine (tpt) ligand and a sulfite anion acting in a so far unreported (in metallorganic compounds) µ2-κ3O,O':O',O" mode (Type 9 in scheme above, and Fig. 2). Both chelating O—S—O angles are almost equal within the determined s.u. values [102.60 (12) and 102.16 (12)°], while the remaining one is larger [106.54 (12)°]. However, the chelates are not completely symmetrical, their S—O distances differing by some 1.5%.
Coordination around the CdII centres generates a dimeric centrosymmetric structure where both monomers are doubly linked via the Cd1—O2—S1—O1—Cd1i and Cd1—O3—Cd1i loops (see Fig. 2 for symmetry codes). The general disposition of the dimer resembles that of an Mn(tpt) complex that we have recently reported {viz. [Mn2(C16H12N6)2(SO4)2(H2O)2]·4H2O; Diaz de Vivar et al., 2006}, where a sulfate group played the role of the actual sulfite. The two structures both have dimeric character and share many other coordination features. The main difference resides in the central O atom, which in the present structure bridges to two symmetry-related cations, while in the sulfate analogue it `breaks' one of these bonds, the O atom leaning towards the remaining cation. The vacant site left in the sevenfold Mn coordination polyhedron is occupied by one aqua molecule.
The organic ligand coordinates via three N-atom donors (N1 and N3 from two pyridine rings and N2 from the triazine ring), leaving the third pyridyl group uncoordinated and rotated by 4.6 (2)° to the central core mean plane. The latter is not strictly planar, the deformation being mainly due to the misalignment of the individual pyridyl and triazine components [the range of interplanar angles is 0.2 (2)–10.4 (2)°]. The coordination mode displayed by tpt is its most common one; a search of the CSD showed that 89% of the reported complexes containing the ligand adopt this tridentated bite to the cation.
Only four structures with tpt coordinating to group 12 metals appear in the CSD, viz. two with ZnII (EYIMUU and PAHTEY), one with CdII (GADLON) and one with HgII (BEJFUR). As in all other reported group 12 t pt complexes, the central metal–N distance [2.353 (2) Å] is shorter than the lateral ones [the mean is 2.434 (20) Å], owing to chelation constraints and the rigid character of the ligand.
The elongated dimer presents a prolate profile with principal axes of very different lengths, viz. 23.9 (1), 11.2 (1) and 4.8 (1) Å, and dimers stack along their shortest direction, in the form of columns oriented parallel to [100] (in heavy lines in Fig. 3). The link between succesive units in the column is the water molecule O3W, through the two hydrogen bonds in which it takes part (entries 1 and 2 in Table 2, and Fig 3). These chains, in turn, interact laterally with neighbouring chains through two different mechanisms, viz. a very long hydrogen-bonding chain [8.54 (2) Å between extreme O2 and O2iv acceptors] involving all four water molecules and their symmetry related counterparts (entries 3 to 7 in Table 2, and Fig 3), and a Cg···Cg interaction between pyridyl groups of the interdigitated tpt ligands (Table 3). The result is a broad two-dimensional structure expanding parallel to the (010) plane. The interaction between these planes is achieved mainly through the strong interaction involving O1W and N6 (entry 8 in Table 2); these are directed straight out of the paper and are therefore not represented in Fig. 3.