Single-crystal study of the m = 2 tubular cobalt oxide, Bi₄Sr₁₂Co₈O_30−δ

The structure of the = 2 tubular compound Bi₄Sr₁₂Co₈O_30−δ, bismuth strontium cobalt oxide, was determined by single-crystal X-ray diffraction. This phase of orthorhombic symmetry exhibits a very strong tetragonal pseudosymmetry. The structure consists of 90°-oriented Bi₂Sr₂CoO_6+δ slices, four Co atoms wide, forming [Sr₄Co₄O₁₃]_∞ pillars at their intersection. The Co atoms in these pillars form four corner-sharing CoO₅ bipyramids. In the resulting [Co₄O₁₃] cluster, an anionic disorder is evidenced and discussed. Then, an accurate description of the particular structure of the pillars is given. Finally, a comparison with the Mn tubular compound Bi_3.6Sr_12.4Mn₈O_30−δ is carried out.

Computing details

(I)

Crystal data

BiCo2Sr3O8.25	F(000) = 4976
Mr = 721.7	Dx = 6.301 Mg m^−3
Orthorhombic, C222	Mo Kα radiation, λ = 0.7107 Å
a = 23.4782 Å	Cell parameters from 25 reflections
b = 23.4857 Å	µ = 49.80 mm^−1
c = 5.5171 Å	T = 293 K
V = 3042.14 Å^3	Needle, black
Z = 16	0.20 × 0.06 × 0.03 mm

Data collection

Brucker-SMART diffractometer	5185 reflections with 3
Absorption correction: gaussian Integration	Rint = 0.038
Tmin = 0.050, Tmax = 0.200	h = →
27412 measured reflections	k = →
13706 independent reflections	l = →

Refinement

Refinement on F	Weighting scheme based on measured s.u.'s w = 1/σ^2(F)
R[F^2 > 2σ(F^2)] = 0.059	(Δ/σ)max = 0.001
wR(F^2) = 0.049	Δρmax = 5.6 e Å^−3
S = 2.66	Δρmin = −5.6 e Å^−3
5185 reflections	Extinction correction: B-C type 1 Gaussian isotropic
165 parameters	Extinction coefficient: 0.040441

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

	x	y	z	Uiso*/Ueq
Bi1	0.061551 (18)	0.055780 (19)	0.7689 (2)	0.00694 (13)
Bi2	0.444236 (18)	0.061594 (19)	0.7336 (2)	0.00782 (13)
Co1	0.16481 (6)	0.24775 (8)	0.2447 (11)	0.0124 (4)
Co2	0.05601 (6)	0.24203 (7)	0.7537 (9)	0.0119 (4)
Co3	0.25214 (7)	0.16459 (7)	0.2622 (11)	0.0114 (5)
Co4	0.25768 (7)	0.05615 (7)	0.7471 (9)	0.0122 (4)
Sr1	0.05603 (5)	0.16706 (5)	0.2477 (6)	0.0103 (3)
Sr2	0.16954 (5)	0.16468 (4)	0.7503 (6)	0.0159 (3)
Sr3	0.17582 (5)	0.05396 (6)	0.2465 (7)	0.0094 (4)
Sr4	0.44631 (5)	0.17588 (6)	0.2478 (7)	0.0093 (4)
Sr5	0.33520 (4)	0.16952 (5)	0.7561 (5)	0.0156 (3)
Sr6	0.33289 (4)	0.05591 (6)	0.2461 (6)	0.0101 (3)
O1	0	0.2450 (6)	0	0.010 (3)*
O2	0	0.2495 (9)	0.5	0.021 (6)*
O3	0.1141 (6)	0.2443 (5)	0.006 (3)	0.019 (3)*
O4	0.1182 (9)	0.2477 (8)	0.533 (4)	0.024 (6)*
O5	0.2512 (9)	0.1107 (15)	0.005 (6)	0.033 (11)*
O6	0.2538 (4)	0.1196 (4)	0.525 (2)	0.0027 (17)*
O7	0.2572 (7)	0	0.5	0.016 (4)*
O8	0.2521 (6)	0	0	0.011 (4)*
O9	0.0561 (3)	0.1472 (3)	0.7122 (18)	0.0036 (15)*
O10	0.1697 (4)	0.1653 (4)	0.252 (3)	0.020 (2)*
O11	0.1505 (3)	0.0547 (4)	0.749 (2)	0.0131 (16)*
O12	0.5544 (3)	0.1496 (3)	0.250 (2)	0.0120 (16)*
O13	0.6656 (4)	0.1689 (4)	0.766 (3)	0.022 (2)*
O14	0.6475 (3)	0.0561 (3)	0.2126 (18)	0.0056 (15)*
O15	0.0691 (3)	0.0623 (4)	0.1427 (17)	0.0124 (19)*
O16	0.5617 (4)	0.0702 (4)	0.6424 (17)	0.017 (2)*
O17	0.25	0.25	0.25	0.181852
O18	0.25	0.25	0.75	0.056138

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Bi1	0.00683 (17)	0.00604 (14)	0.0079 (3)	0.00025 (17)	−0.0008 (2)	0.0003 (3)
Bi2	0.00655 (16)	0.00595 (15)	0.0110 (3)	0.00048 (17)	−0.0007 (3)	0.0000 (2)
Co1	0.0108 (7)	0.0061 (6)	0.0202 (10)	0.0000 (6)	−0.0071 (17)	−0.0022 (8)
Co2	0.0068 (6)	0.0214 (8)	0.0074 (8)	0.0012 (6)	−0.0058 (12)	0.0043 (12)
Co3	0.0069 (7)	0.0099 (7)	0.0174 (12)	−0.0010 (6)	−0.0025 (8)	−0.0048 (15)
Co4	0.0223 (8)	0.0061 (6)	0.0083 (8)	−0.0008 (6)	0.0047 (12)	−0.0020 (13)
Sr1	0.0089 (4)	0.0081 (4)	0.0140 (7)	0.0014 (4)	−0.0022 (9)	0.0011 (8)
Sr2	0.0140 (4)	0.0121 (4)	0.0217 (7)	−0.0021 (4)	−0.0031 (9)	0.0008 (7)
Sr3	0.0082 (5)	0.0078 (5)	0.0123 (9)	0.0010 (4)	0.0029 (11)	0.0047 (11)
Sr4	0.0086 (5)	0.0072 (5)	0.0120 (9)	0.0008 (4)	0.0042 (11)	0.0009 (11)
Sr5	0.0139 (4)	0.0133 (4)	0.0195 (7)	−0.0006 (4)	0.0015 (7)	0.0021 (9)
Sr6	0.0086 (4)	0.0086 (4)	0.0132 (7)	−0.0004 (4)	0.0034 (7)	−0.0058 (9)
O17	0.012334	0.007316	0.525906	−0.006822	0	0
O18	0.024537	0.011623	0.132254	−0.011415	0	0

Bond lengths (Å)

Bi1—Bi1^i	3.9010 (6)	Co2—O12^xii	4.549 (10)
Bi1—Bi1^ii	3.9580 (12)	Co2—O12^xvii	2.546 (7)
Bi1—Bi1^iii	3.6564 (12)	Co2—O13^xvii	4.385 (14)
Bi1—Bi1^iv	4.1418 (12)	Co2—O13^xviii	4.244 (14)
Bi1—Bi1^v	3.8546 (11)	Co2—O15^vi	4.745 (10)
Bi1—Co2	4.3769 (18)	Co2—O16^xvii	4.923 (10)
Bi1—Co4	4.6063 (17)	Co2—O18	4.5584 (15)
Bi1—Sr1	3.888 (3)	Co3—Co1	2.833 (2)
Bi1—Sr1^vi	3.718 (3)	Co3—Co1^xi	2.837 (2)
Bi1—Sr1^iv	3.8026 (12)	Co3—Co3^xi	4.013 (2)
Bi1—Sr2	3.6028 (12)	Co3—Co4^xiv	3.818 (6)
Bi1—Sr3	3.938 (3)	Co3—Co4	3.696 (6)
Bi1—Sr3^vi	3.761 (3)	Co3—Sr1	4.605 (2)
Bi1—Sr3^ii	3.7212 (13)	Co3—Sr2^xiv	3.426 (6)
Bi1—O1^vi	4.845 (14)	Co3—Sr2	3.319 (6)
Bi1—O2	4.999 (18)	Co3—Sr3	3.158 (2)
Bi1—O3^vi	4.780 (13)	Co3—Sr4	4.567 (2)
Bi1—O4	4.876 (19)	Co3—Sr5^xiv	3.408 (5)
Bi1—O5^vi	4.82 (2)	Co3—Sr5	3.353 (5)
Bi1—O6	4.943 (9)	Co3—Sr6	3.181 (2)
Bi1—O8^vi	4.834 (13)	Co3—O3	4.000 (14)
Bi1—O9	2.173 (7)	Co3—O3^xi	4.053 (14)
Bi1—O9^iv	4.392 (8)	Co3—O4	3.99 (2)
Bi1—O9^v	4.521 (8)	Co3—O4^xi	3.97 (2)
Bi1—O10	4.601 (13)	Co3—O5	1.90 (3)
Bi1—O10^vi	4.491 (13)	Co3—O5^vi	4.29 (3)
Bi1—O11	2.092 (7)	Co3—O6^xiv	4.201 (12)
Bi1—O11^ii	4.390 (10)	Co3—O6	1.795 (12)
Bi1—O11^iii	4.261 (10)	Co3—O7	4.084 (2)
Bi1—O15	3.463 (9)	Co3—O8	4.127 (3)
Bi1—O15^vi	2.076 (9)	Co3—O10	1.937 (9)
Bi1—O15^vii	4.621 (9)	Co3—O10^xi	4.398 (9)
Bi1—O15^ii	2.822 (10)	Co3—O11^xiv	4.512 (11)
Bi1—O15^iv	3.110 (8)	Co3—O11	4.425 (11)
Bi2—Bi2^viii	3.9021 (6)	Co3—O13^xvii	4.409 (10)
Bi2—Bi2^ii	3.8748 (12)	Co3—O13^ix	1.940 (9)
Bi2—Bi2^iii	4.1245 (13)	Co3—O14^xix	4.347 (9)
Bi2—Bi2^ix	3.6742 (12)	Co3—O14^ix	4.520 (9)
Bi2—Bi2^x	3.9367 (13)	Co3—O15	4.967 (9)
Bi2—Co2^xi	4.6134 (18)	Co3—O16^ix	4.928 (9)
Bi2—Co4	4.3825 (17)	Co3—O17	2.0076 (17)
Bi2—Sr4	3.793 (3)	Co3—O18^xiv	3.466 (5)
Bi2—Sr4^vi	3.906 (3)	Co3—O18	3.357 (5)
Bi2—Sr4^ix	3.7174 (14)	Co4—Bi1	4.6063 (17)
Bi2—Sr5	3.6048 (12)	Co4—Bi2	4.3825 (17)
Bi2—Sr6	3.753 (2)	Co4—Co3	3.696 (6)
Bi2—Sr6^vi	3.853 (2)	Co4—Co3^vi	3.818 (6)
Bi2—Sr6^ii	3.8029 (13)	Co4—Co4^ii	3.793 (5)
Bi2—O1^xii	4.949 (14)	Co4—Co4^iii	3.840 (5)
Bi2—O2^xi	4.802 (19)	Co4—Sr2	3.283 (2)
Bi2—O3^xii	4.992 (13)	Co4—Sr3	3.365 (5)
Bi2—O4^xi	4.840 (19)	Co4—Sr3^vi	3.360 (5)
Bi2—O5^vi	4.91 (2)	Co4—Sr3^ii	3.222 (2)
Bi2—O6	4.813 (9)	Co4—Sr5	3.226 (2)
Bi2—O7	4.800 (15)	Co4—Sr6	3.280 (5)
Bi2—O8^vi	4.959 (13)	Co4—Sr6^vi	3.271 (5)
Bi2—O12	4.254 (10)	Co4—Sr6^ii	3.170 (2)
Bi2—O12^vi	4.367 (10)	Co4—O5	4.29 (3)
Bi2—O12^ix	2.069 (7)	Co4—O5^vi	1.92 (3)
Bi2—O13^ix	4.540 (14)	Co4—O5^ii	4.15 (3)
Bi2—O13^x	4.541 (14)	Co4—O6	1.931 (11)
Bi2—O14^viii	4.533 (9)	Co4—O6^vi	4.545 (12)
Bi2—O14^xiii	4.390 (9)	Co4—O6^ii	4.394 (10)
Bi2—O14^ix	2.178 (6)	Co4—O7	1.897 (4)
Bi2—O16	2.811 (9)	Co4—O7^vi	4.358 (5)
Bi2—O16^viii	3.140 (10)	Co4—O8	4.329 (5)
Bi2—O16^ii	4.636 (10)	Co4—O8^vi	1.924 (4)
Bi2—O16^ix	2.089 (10)	Co4—O10	4.276 (14)
Bi2—O16^x	3.452 (10)	Co4—O10^vi	4.314 (14)
Co1—Co1^xi	4.002 (2)	Co4—O11	2.516 (7)
Co1—Co2^xiv	3.726 (6)	Co4—O11^ii	4.540 (10)
Co1—Co2	3.798 (6)	Co4—O11^iii	4.563 (10)
Co1—Co3	2.833 (2)	Co4—O12^ix	4.927 (7)
Co1—Co3^xi	2.837 (2)	Co4—O13^ix	4.275 (15)
Co1—Sr1	3.180 (2)	Co4—O13^x	4.179 (14)
Co1—Sr2^xiv	3.356 (6)	Co4—O14^viii	4.539 (9)
Co1—Sr2	3.406 (6)	Co4—O14^xiii	4.302 (9)
Co1—Sr3	4.559 (2)	Co4—O14^ix	2.237 (6)
Co1—Sr4^xi	3.166 (2)	Co4—O15^vi	4.938 (9)
Co1—Sr5^xv	3.323 (6)	Co4—O16^ix	4.765 (10)
Co1—Sr5^xi	3.425 (6)	Co4—O18	4.5562 (17)
Co1—Sr6^xi	4.611 (2)	Sr1—O1	2.637 (11)
Co1—O1	4.099 (2)	Sr1—O2	2.724 (14)
Co1—O2	4.118 (2)	Sr1—O3	2.632 (14)
Co1—O3	1.776 (15)	Sr1—O4	2.86 (2)
Co1—O3^vi	4.367 (16)	Sr1—O9^xiv	2.991 (11)
Co1—O4^xiv	4.07 (2)	Sr1—O9	2.605 (11)
Co1—O4	1.93 (2)	Sr1—O9^iv	2.684 (7)
Co1—O5	4.03 (3)	Sr1—O10	2.669 (9)
Co1—O5^xi	4.08 (3)	Sr1—O15	2.546 (10)
Co1—O6	3.977 (10)	Sr2—O3^vi	2.680 (14)
Co1—O6^xi	3.968 (10)	Sr2—O4	2.59 (2)
Co1—O9^xiv	4.552 (9)	Sr2—O5^vi	2.69 (3)
Co1—O9	4.329 (9)	Sr2—O6	2.565 (10)
Co1—O10	1.941 (10)	Sr2—O9	2.702 (7)
Co1—O10^xi	4.391 (9)	Sr2—O10	2.747 (19)
Co1—O12^xvi	4.469 (11)	Sr2—O10^vi	2.770 (19)
Co1—O12^xvii	4.506 (11)	Sr2—O11	2.622 (9)
Co1—O13^xvii	1.958 (10)	Sr2—O18	2.7538 (11)
Co1—O13^ix	4.391 (9)	Sr3—O5	2.59 (3)
Co1—O15	4.933 (10)	Sr3—O6	2.845 (10)
Co1—O16^xvii	4.952 (10)	Sr3—O7	2.686 (12)
Co1—O17	2.0010 (14)	Sr3—O8	2.582 (10)
Co1—O18^xiv	3.384 (5)	Sr3—O10	2.618 (9)
Co1—O18	3.431 (5)	Sr3—O11^xiv	2.806 (13)
Co2—Bi1	4.3769 (18)	Sr3—O11	2.838 (13)
Co2—Bi2^xi	4.6134 (18)	Sr3—O11^ii	2.620 (9)
Co2—Co1	3.798 (6)	Sr3—O15	2.578 (8)
Co2—Co1^vi	3.726 (6)	Sr4—O1^xi	2.628 (11)
Co2—Co2^iv	3.841 (5)	Sr4—O2^xi	2.568 (14)
Co2—Co2^v	3.782 (5)	Sr4—O3^xi	2.702 (14)
Co2—Sr1	3.301 (5)	Sr4—O4^xi	2.83 (2)
Co2—Sr1^vi	3.245 (5)	Sr4—O12	2.613 (7)
Co2—Sr1^iv	3.165 (2)	Sr4—O12^xix	2.813 (13)
Co2—Sr2	3.2257 (19)	Sr4—O12^ix	2.840 (13)
Co2—Sr4^xi	3.393 (5)	Sr4—O13^ix	2.634 (9)
Co2—Sr4^xii	3.339 (5)	Sr4—O16^ix	2.561 (10)
Co2—Sr4^xvii	3.217 (2)	Sr5—O3^xii	2.723 (13)
Co2—Sr5^xi	3.2923 (19)	Sr5—O4^xi	2.55 (2)
Co2—O1	4.362 (5)	Sr5—O5^vi	2.77 (3)
Co2—O1^vi	1.892 (4)	Sr5—O6	2.578 (10)
Co2—O2	1.929 (4)	Sr5—O12^ix	2.633 (7)
Co2—O2^vi	4.326 (5)	Sr5—O13^ix	2.882 (19)
Co2—O3	4.344 (15)	Sr5—O13^x	2.635 (19)
Co2—O3^vi	1.951 (15)	Sr5—O14^ix	2.699 (8)
Co2—O3^iv	4.209 (14)	Sr5—O18	2.7521 (11)
Co2—O4	1.90 (2)	Sr6—O5	2.67 (3)
Co2—O4^vi	4.55 (2)	Sr6—O6	2.838 (10)
Co2—O4^iv	4.39 (2)	Sr6—O7	2.616 (12)
Co2—O9	2.239 (7)	Sr6—O8	2.676 (10)
Co2—O9^iv	4.301 (9)	Sr6—O13^ix	2.655 (10)
Co2—O9^v	4.536 (9)	Sr6—O14^viii	2.678 (8)
Co2—O10	4.245 (14)	Sr6—O14^xix	2.572 (10)
Co2—O10^vi	4.236 (14)	Sr6—O14^ix	3.021 (10)
Co2—O11	4.928 (9)	Sr6—O16^ix	2.572 (9)
Co2—O12^xi	4.575 (10)

Symmetry codes: (i) −x, −y, z; (ii) x, −y, −z+1; (iii) x, −y, −z+2; (iv) −x, y, −z+1; (v) −x, y, −z+2; (vi) x, y, z+1; (vii) −x, −y, z+1; (viii) −x+1, −y, z; (ix) −x+1, y, −z+1; (x) −x+1, y, −z+2; (xi) −x+1/2, −y+1/2, z; (xii) −x+1/2, −y+1/2, z+1; (xiii) −x+1, −y, z+1; (xiv) x, y, z−1; (xv) −x+1/2, −y+1/2, z−1; (xvi) x−1/2, −y+1/2, −z; (xvii) x−1/2, −y+1/2, −z+1; (xviii) x−1/2, −y+1/2, −z+2; (xix) −x+1, y, −z.