K4C2H6O9 crystallizes in the monoclinic C2/c space group. There are three inequivalent K sites. In the first K site, K(1) is bonded in a 8-coordinate geometry to two equivalent H(2), two equivalent O(1), two equivalent O(2), and two equivalent O(5) atoms. In the second K site, K(2) is bonded in a 10-coordinate geometry to two equivalent H(3), two equivalent O(1), two equivalent O(2), two equivalent O(3), and two equivalent O(5) atoms. In the third K site, K(3) is bonded in a 10-coordinate geometry to one H(1), one H(3), one O(3), one O(4), one O(5), two equivalent O(2), and three equivalent O(1) atoms. C(1) is bonded in a trigonal planar geometry to one O(1), one O(2), and one O(3) atom. There are three inequivalent H sites. In the first H site, H(1) is bonded in a distorted single-bond geometry to one K(3) and one O(4) atom. In the second H site, H(2) is bonded in a single-bond geometry to one K(1) and one O(5) atom. In the third H site, H(3) is bonded in a distorted single-bond geometry to one K(2), one K(3), and one O(5) atom. There are five inequivalent O sites. In the first O site, O(1) is bonded in a distorted single-bond geometry to one K(1), one K(2), three equivalent K(3), and one C(1) atom. In the second O site, O(2) is bonded in a distorted single-bond geometry to one K(1), one K(2), two equivalent K(3), and one C(1) atom. In the third O site, O(3) is bonded in a distorted single-bond geometry to one K(2), one K(3), and one C(1) atom. In the fourth O site, O(4) is bonded in a water-like geometry to two equivalent K(3) and two equivalent H(1) atoms. In the fifth O site, O(5) is bonded in a water-like geometry to one K(1), one K(2), one K(3), one H(2), and one H(3) atom.
K4C2H6O9 crystallizes in the monoclinic C2/c space group. There are three inequivalent K sites. In the first K site, K(1) is bonded in a 8-coordinate geometry to two equivalent H(2), two equivalent O(1), two equivalent O(2), and two equivalent O(5) atoms. Both K(1)-H(2) bond lengths are 2.76 Å. Both K(1)-O(1) bond lengths are 2.83 Å. Both K(1)-O(2) bond lengths are 2.78 Å. Both K(1)-O(5) bond lengths are 2.80 Å. In the second K site, K(2) is bonded in a 10-coordinate geometry to two equivalent H(3), two equivalent O(1), two equivalent O(2), two equivalent O(3), and two equivalent O(5) atoms. Both K(2)-H(3) bond lengths are 2.85 Å. Both K(2)-O(1) bond lengths are 2.78 Å. Both K(2)-O(2) bond lengths are 2.85 Å. Both K(2)-O(3) bond lengths are 3.14 Å. Both K(2)-O(5) bond lengths are 2.94 Å. In the third K site, K(3) is bonded in a 10-coordinate geometry to one H(1), one H(3), one O(3), one O(4), one O(5), two equivalent O(2), and three equivalent O(1) atoms. The K(3)-H(1) bond length is 2.97 Å. The K(3)-H(3) bond length is 2.79 Å. The K(3)-O(3) bond length is 2.91 Å. The K(3)-O(4) bond length is 2.82 Å. The K(3)-O(5) bond length is 2.99 Å. Both K(3)-O(2) bond lengths are 2.92 Å. There are a spread of K(3)-O(1) bond distances ranging from 2.82-3.22 Å. C(1) is bonded in a trigonal planar geometry to one O(1), one O(2), and one O(3) atom. The C(1)-O(1) bond length is 1.29 Å. The C(1)-O(2) bond length is 1.31 Å. The C(1)-O(3) bond length is 1.31 Å. There are three inequivalent H sites. In the first H site, H(1) is bonded in a distorted single-bond geometry to one K(3) and one O(4) atom. The H(1)-O(4) bond length is 1.00 Å. In the second H site, H(2) is bonded in a single-bond geometry to one K(1) and one O(5) atom. The H(2)-O(5) bond length is 1.00 Å. In the third H site, H(3) is bonded in a distorted single-bond geometry to one K(2), one K(3), and one O(5) atom. The H(3)-O(5) bond length is 1.01 Å. There are five inequivalent O sites. In the first O site, O(1) is bonded in a distorted single-bond geometry to one K(1), one K(2), three equivalent K(3), and one C(1) atom. In the second O site, O(2) is bonded in a distorted single-bond geometry to one K(1), one K(2), two equivalent K(3), and one C(1) atom. In the third O site, O(3) is bonded in a distorted single-bond geometry to one K(2), one K(3), and one C(1) atom. In the fourth O site, O(4) is bonded in a water-like geometry to two equivalent K(3) and two equivalent H(1) atoms. In the fifth O site, O(5) is bonded in a water-like geometry to one K(1), one K(2), one K(3), one H(2), and one H(3) atom.