Co19(BSi2)4 crystallizes in the monoclinic C2 space group. There are ten inequivalent Co sites. In the first Co site, Co(1) is bonded in a 2-coordinate geometry to two equivalent Co(7), one B(2), one B(3), one Si(2), one Si(4), and two equivalent Si(3) atoms. In the second Co site, Co(2) is bonded in a 4-coordinate geometry to one B(1), one B(3), one Si(1), one Si(3), and two equivalent Si(4) atoms. In the third Co site, Co(3) is bonded in a 4-coordinate geometry to one Co(7), one B(1), one B(3), one Si(3), and two equivalent Si(1) atoms. In the fourth Co site, Co(4) is bonded in a 2-coordinate geometry to two equivalent Co(7), one B(2), one B(3), one Si(1), one Si(4), and two equivalent Si(2) atoms. In the fifth Co site, Co(5) is bonded in a 2-coordinate geometry to one Co(7), one B(1), one B(3), one Si(1), one Si(2), one Si(3), and one Si(4) atom. In the sixth Co site, Co(6) is bonded in a 4-coordinate geometry to one Co(7), one B(2), one B(3), one Si(1), one Si(3), and one Si(4) atom. In the seventh Co site, Co(7) is bonded in a 14-coordinate geometry to one Co(10), one Co(3), one Co(5), one Co(6), two equivalent Co(1), two equivalent Co(4), one B(2), one B(3), one Si(3), one Si(4), and two equivalent Si(2) atoms. In the eighth Co site, Co(8) is bonded in a 4-coordinate geometry to one B(1), one B(3), one Si(3), one Si(4), and two equivalent Si(1) atoms. In the ninth Co site, Co(9) is bonded in a 6-coordinate geometry to two equivalent Co(10), two equivalent Si(1), and two equivalent Si(4) atoms. In the tenth Co site, Co(10) is bonded in a 5-coordinate geometry to one Co(7), one Co(9), one Si(1), one Si(2), one Si(3), and one Si(4) atom. There are three inequivalent B sites. In the first B site, B(1) is bonded in a 10-coordinate geometry to two equivalent Co(2), two equivalent Co(3), two equivalent Co(5), two equivalent Co(8), and two equivalent B(3) atoms. In the second B site, B(2) is bonded in a 10-coordinate geometry to two equivalent Co(1), two equivalent Co(4), two equivalent Co(6), two equivalent Co(7), and two equivalent B(3) atoms. In the third B site, B(3) is bonded in a 10-coordinate geometry to one Co(1), one Co(2), one Co(3), one Co(4), one Co(5), one Co(6), one Co(7), one Co(8), one B(1), and one B(2) atom. There are four inequivalent Si sites. In the first Si site, Si(1) is bonded in a 10-coordinate geometry to one Co(10), one Co(2), one Co(4), one Co(5), one Co(6), one Co(9), two equivalent Co(3), and two equivalent Co(8) atoms. In the second Si site, Si(2) is bonded in a 7-coordinate geometry to one Co(1), one Co(10), one Co(5), two equivalent Co(4), and two equivalent Co(7) atoms. In the third Si site, Si(3) is bonded in a 9-coordinate geometry to one Co(10), one Co(2), one Co(3), one Co(5), one Co(6), one Co(7), one Co(8), and two equivalent Co(1) atoms. In the fourth Si site, Si(4) is bonded in a 10-coordinate geometry to one Co(1), one Co(10), one Co(4), one Co(5), one Co(6), one Co(7), one Co(8), one Co(9), and two equivalent Co(2) atoms.
Co19(BSi2)4 crystallizes in the monoclinic C2 space group. There are ten inequivalent Co sites. In the first Co site, Co(1) is bonded in a 2-coordinate geometry to two equivalent Co(7), one B(2), one B(3), one Si(2), one Si(4), and two equivalent Si(3) atoms. There is one shorter (2.63 Å) and one longer (2.72 Å) Co(1)-Co(7) bond length. The Co(1)-B(2) bond length is 2.14 Å. The Co(1)-B(3) bond length is 2.15 Å. The Co(1)-Si(2) bond length is 2.31 Å. The Co(1)-Si(4) bond length is 2.46 Å. There is one shorter (2.35 Å) and one longer (2.38 Å) Co(1)-Si(3) bond length. In the second Co site, Co(2) is bonded in a 4-coordinate geometry to one B(1), one B(3), one Si(1), one Si(3), and two equivalent Si(4) atoms. The Co(2)-B(1) bond length is 2.19 Å. The Co(2)-B(3) bond length is 2.16 Å. The Co(2)-Si(1) bond length is 2.30 Å. The Co(2)-Si(3) bond length is 2.71 Å. There is one shorter (2.37 Å) and one longer (2.58 Å) Co(2)-Si(4) bond length. In the third Co site, Co(3) is bonded in a 4-coordinate geometry to one Co(7), one B(1), one B(3), one Si(3), and two equivalent Si(1) atoms. The Co(3)-Co(7) bond length is 2.64 Å. The Co(3)-B(1) bond length is 2.15 Å. The Co(3)-B(3) bond length is 2.17 Å. The Co(3)-Si(3) bond length is 2.30 Å. There is one shorter (2.36 Å) and one longer (2.57 Å) Co(3)-Si(1) bond length. In the fourth Co site, Co(4) is bonded in a 2-coordinate geometry to two equivalent Co(7), one B(2), one B(3), one Si(1), one Si(4), and two equivalent Si(2) atoms. There is one shorter (2.62 Å) and one longer (2.63 Å) Co(4)-Co(7) bond length. The Co(4)-B(2) bond length is 2.16 Å. The Co(4)-B(3) bond length is 2.13 Å. The Co(4)-Si(1) bond length is 2.45 Å. The Co(4)-Si(4) bond length is 2.31 Å. There is one shorter (2.36 Å) and one longer (2.38 Å) Co(4)-Si(2) bond length. In the fifth Co site, Co(5) is bonded in a 2-coordinate geometry to one Co(7), one B(1), one B(3), one Si(1), one Si(2), one Si(3), and one Si(4) atom. The Co(5)-Co(7) bond length is 2.51 Å. The Co(5)-B(1) bond length is 2.13 Å. The Co(5)-B(3) bond length is 2.15 Å. The Co(5)-Si(1) bond length is 2.46 Å. The Co(5)-Si(2) bond length is 2.36 Å. The Co(5)-Si(3) bond length is 2.38 Å. The Co(5)-Si(4) bond length is 2.31 Å. In the sixth Co site, Co(6) is bonded in a 4-coordinate geometry to one Co(7), one B(2), one B(3), one Si(1), one Si(3), and one Si(4) atom. The Co(6)-Co(7) bond length is 2.49 Å. The Co(6)-B(2) bond length is 2.17 Å. The Co(6)-B(3) bond length is 2.15 Å. The Co(6)-Si(1) bond length is 2.58 Å. The Co(6)-Si(3) bond length is 2.29 Å. The Co(6)-Si(4) bond length is 2.36 Å. In the seventh Co site, Co(7) is bonded in a 14-coordinate geometry to one Co(10), one Co(3), one Co(5), one Co(6), two equivalent Co(1), two equivalent Co(4), one B(2), one B(3), one Si(3), one Si(4), and two equivalent Si(2) atoms. The Co(7)-Co(10) bond length is 2.77 Å. The Co(7)-B(2) bond length is 2.13 Å. The Co(7)-B(3) bond length is 2.17 Å. The Co(7)-Si(3) bond length is 2.34 Å. The Co(7)-Si(4) bond length is 2.46 Å. There is one shorter (2.31 Å) and one longer (2.38 Å) Co(7)-Si(2) bond length. In the eighth Co site, Co(8) is bonded in a 4-coordinate geometry to one B(1), one B(3), one Si(3), one Si(4), and two equivalent Si(1) atoms. The Co(8)-B(1) bond length is 2.17 Å. The Co(8)-B(3) bond length is 2.14 Å. The Co(8)-Si(3) bond length is 2.72 Å. The Co(8)-Si(4) bond length is 2.57 Å. There is one shorter (2.30 Å) and one longer (2.36 Å) Co(8)-Si(1) bond length. In the ninth Co site, Co(9) is bonded in a 6-coordinate geometry to two equivalent Co(10), two equivalent Si(1), and two equivalent Si(4) atoms. Both Co(9)-Co(10) bond lengths are 2.42 Å. Both Co(9)-Si(1) bond lengths are 2.27 Å. Both Co(9)-Si(4) bond lengths are 2.27 Å. In the tenth Co site, Co(10) is bonded in a 5-coordinate geometry to one Co(7), one Co(9), one Si(1), one Si(2), one Si(3), and one Si(4) atom. The Co(10)-Si(1) bond length is 2.34 Å. The Co(10)-Si(2) bond length is 2.21 Å. The Co(10)-Si(3) bond length is 2.21 Å. The Co(10)-Si(4) bond length is 2.35 Å. There are three inequivalent B sites. In the first B site, B(1) is bonded in a 10-coordinate geometry to two equivalent Co(2), two equivalent Co(3), two equivalent Co(5), two equivalent Co(8), and two equivalent B(3) atoms. Both B(1)-B(3) bond lengths are 2.10 Å. In the second B site, B(2) is bonded in a 10-coordinate geometry to two equivalent Co(1), two equivalent Co(4), two equivalent Co(6), two equivalent Co(7), and two equivalent B(3) atoms. Both B(2)-B(3) bond lengths are 2.13 Å. In the third B site, B(3) is bonded in a 10-coordinate geometry to one Co(1), one Co(2), one Co(3), one Co(4), one Co(5), one Co(6), one Co(7), one Co(8), one B(1), and one B(2) atom. There are four inequivalent Si sites. In the first Si site, Si(1) is bonded in a 10-coordinate geometry to one Co(10), one Co(2), one Co(4), one Co(5), one Co(6), one Co(9), two equivalent Co(3), and two equivalent Co(8) atoms. In the second Si site, Si(2) is bonded in a 7-coordinate geometry to one Co(1), one Co(10), one Co(5), two equivalent Co(4), and two equivalent Co(7) atoms. In the third Si site, Si(3) is bonded in a 9-coordinate geometry to one Co(10), one Co(2), one Co(3), one Co(5), one Co(6), one Co(7), one Co(8), and two equivalent Co(1) atoms. In the fourth Si site, Si(4) is bonded in a 10-coordinate geometry to one Co(1), one Co(10), one Co(4), one Co(5), one Co(6), one Co(7), one Co(8), one Co(9), and two equivalent Co(2) atoms.