Crystal structures of two heterotrimetallic dysprosium–manganese–sodium 12-metallacrown-4 complexes with the bridging ligands 3-hydroxybenzoate and 4-hydroxybenzoate

The metallacrown complexes DyIIINa(3-OHben)4[12-MCMn(III)N(shi)-4](H2O)4·10DMA, 1, and DyIIINa(4-OHben)4[12-MCMn(III)N(shi)-4](H2O)4·4DMF, 2, where MC is metallacrown, shi3− is salicylhydroximate, 3-OHben is 3-hydroxybenzoate, DMA is N,N-dimethylacetamide, 4-OHben is 4-hydroxybenzoate, and DMF is N,N-dimethylformamide, consist of a macrocyclic molecule with an [MnIII—N—O] repeat unit. For both 1 and 2, a DyIII ion is captured on the convex side of the central cavity, while a Na+ ion is captured on the concave side of the cavity. Four 3-hydroxybenzoate or 4-hydroxybenzoate anions bridge between the ring MnIII ions and the central DyIII ion.


Chemical context
Metallacrowns (MC) were first discovered in 1989 by Pecoraro, and the compounds have grown into a class of coordination complexes with a wide range of applications including single-molecule magnets, magnetorefrigerants, ISSN 2056-9890 luminescent agents, cell imaging agents, and magnetic resonance imaging agents (Mezei et al., 2007;Nguyen & Pecoraro, 2017;Lutter et al., 2018;Anthanasopoulou et al., 2018). MCs, the inorganic equivalent of crown ethers, are macrocyclic molecules that follow a metal-nitrogen-oxygen [M-N-O] repeat in the ring of the molecule, similar to the carboncarbon-oxygen [C-C-O] repeat of a crown ether. The selfassembly synthetic strategy of MCs lends itself to the ability to place metal ions in specific positions in the molecules and the controllable formation of specific molecules. While heterobimetallic MCs have been known since the 1990s, heterotrimetallic MCs have only been recently reported (Azar et al., 2014;Travis et al., 2015Travis et al., , 2016Cao et al., 2016;Boron et al., 2016;Lutter et al., 2020). These structures are based on a 12-MC-4 framework with manganese(III) or gallium(III) as the ring metal, a central lanthanide ion, and typically an alkali metal ion bound opposite to the lanthanide ion -though in one case a tungsten(V) ion is bound opposite the lanthanide ion. In general, the controllable formation of heterotrimetallic systems remains difficult from a synthetic perspective; however, MCs provide a pathway that demonstrates that such systems are achievable in a straightforward and predictable fashion.
In 2014 we reported a series of Ln III Na(OAc) 4 [12-MC Mn(III)N(shi) -4](H 2 O) 4 complexes, where Ln III is Pr III to Yb III (except Pm III ) and Y III , À OAc is acetate, and shi 3À is salicylhydroximate, that were the first heterotrimetallic MCs and the first 12-MC-4 complexes to bind a lanthanide ion in the central cavity (Azar et al., 2014). The lanthanide ion is tethered to the MC via four acetate bridges that link the central Ln III to the ring Mn III ions. Since then we have reported other Ln III Na(X) 4 [12-MC Mn(III)N(shi) -4] complexes, where Ln III is Y III , Er III , and Dy III , and X À is 2-hydroxybenzoate, benzoate, and trimethylacetate, which demonstrate that the bridging carboxylate anion can be easily substituted in these structures (Travis et al., 2015(Travis et al., , 2016Boron et al., 2016). In addition, the identity of the bridging ligand affects the singlemolecule magnet (SMM) properties of a series of [12-MC Mn(III)N(shi) -4] complexes with Dy III as the central lanthanide ion (Boron et al., 2016). Specifically, the pK a value of the parent acid of the bridging ligand, which indicates the Lewis basicity of the anion, directly impacts the SMM behavior of the MCs. Only the 2-hydroxybenzoate (i.e. salicylate) version of the MCs behaves as an SMM, while the benzoate, acetate, and trimethylacetate analogues do not possess any SMM behavior. 2-Hydroxybenzoic acid has the smallest pK a value (2.98) of the species investigated, and the subsequent pK a values increase from benzoic acid (4.20) to acetic acid (4.76) to trimethylacetic acid (5.03). Thus, 2-hydroxybenzoate is the most electron-withdrawing of the set of anions, and this could affect the magnetic coupling between the ring Mn III ions and central Dy III ion.

Structural commentary
The metallacrown complexes Dy III Na(3-OHben) 4 [12-MC Mn(III)N(shi) -4](H 2 O) 4 Á10DMA, 1, and Dy III Na(4-OHben) 4 -[12-MC Mn(III)N(shi) -4](H 2 O) 4 Á4DMF, 2, both possess the typical 12-MC-4 framework with a repeat unit of Mn III -N-O that recurs four times to generate an approximately square-shaped molecule ( Figs. 1 and 2). Each MC contains one Dy III ion, one Na + ion, and four Mn III ions, which provides a total 16+ charge. This positive charge is counterbalanced by the four shi 3À ligands and four carboxylate anions of the MCs (total 16À charge). Beyond overall molecular charge considerations, the metal oxidation states are confirmed by average bond lengths and bond-valence sum (BVS) values (Table 1; Thorp, 1993 andTrzesowska et al., 2004). The four Mn III ions and four shi 3À ligands provide an MC framework that is able to bind the two central ions. The oxime oxygen atoms of the shi 3À ligands form the central MC cavity that binds Dy III and Na + ions on opposite faces of the MC. The metallacrown is slightly domed with the Dy III ion bound to the convex side of the MC cavity and the Na + ion attached to the concave side. The single-crystal X-ray structure of Dy III Na(4-OHben) 4 [12-MC Mn(III)N(shi) -4](H 2 O) 4 Á4DMF, 2, (a) top view with only the metal atoms and shi 3À ligands labeled for clarity and (b) side view with only the metal atoms and axial ligands labeled for clarity. The displacement ellipsoids are drawn at the 50% probability level. For clarity, hydrogen atoms, solvent molecules, and disorder have been omitted. See Fig. 1 for additional display details. The single-crystal X-ray structure of Dy III Na(3-OHben) 4 [12-MC Mn(III)N(shi) -4](H 2 O) 4 Á10DMA, 1, (a) top view with only the metal atoms and shi 3À ligands labeled for clarity and (b) side view with only the metal atoms and axial ligands labeled for clarity. The displacement ellipsoids are drawn at the 50% probability level. For clarity, hydrogen atoms, solvent molecules, and disorder have been omitted. Color scheme: purple -Dy III , green -Mn III , yellow -Na + , red -oxygen, blue -nitrogen, and gray -carbon. All figures were generated with the program Mercury (Macrae et al., 2020). [Symmetry codes: (i) +x, Ày + 3 2 , +z; (ii) Àx + 3 2 , Ày + 3 2 , +z; (iii) Àx + 3 2 , +y, +z.] Table 1 Average bond length (Å ) and bond-valence-sum (BVS) values (v.u.) used to support assigned oxidation states of the dysprosium and manganese ions of 1 and 2. As previously reported, the doming effect is likely due to the displacement of the ring metal atoms from the equatorial plane of the first coordination sphere ligand atoms (Azar et al., 2014). For both 1 and 2, the average distance of the Mn III ions from the equatorial plane is 0.14 Å . The Dy III ion is further attached to the MC via either four 3-hydroxybenzoate or 4-hydroxybenzoate anions that bridge between the Dy III ion and each ring Mn III ion. For 1 the molecule possesses a fourfold rotation axis along the Dy III and Na + ions, and wholemolecule disorder is observed for the main molecule, excluding only the Dy III and Na + ions, with the occupancy ratio refined to 0.8018 (14): 0.1982 (14). For 2, large sections of the metallacrown are disordered, including the Dy III ion, Mn1, two of the 4-hydroxybenzoate ligands bound to Mn1 and Mn2, the shi 3À ligand that connects Mn1 and Mn4, and portions of the remaining three shi 3À ligands. The occupancy ratio for the metallacrown disorder refined to 0.849 (9):0.151 (9). Complete details describing the treatment of the disorder are given in the Refinement section. The following structural descriptions focus only on the major disorder components. For both 1 and 2, each Mn III ion is six-coordinate, with a tetragonally distorted octahedral geometry. The elongated Jahn-Teller axis along the z direction is expected for a highspin d 4 electron configuration. The geometry assignment is supported by a continuous shape measures (CShM) analysis (SHAPE 2.1; Llunell et al., 2013;Pinsky & Avnir, 1998). The CShM values of the Mn III ions range from 1.115 to 1.434 (Table 2). Typically CShM values less than 1.0 indicate only minor distortions of the assigned geometry from the ideal shape (Cirera et al., 2005), while CShM values up to 3.0 indicate significant distortions from the ideal geometry; however, a value up to 3.0 still represents an acceptable description of the geometry. The CShM values for the Mn III ions are likely greater than 1.0 due to the presence of the Jahn-Teller axis. The elongated Jahn-Teller distortion is composed of a carboxylate oxygen atom from a 3-hydroxybenzoate or 4-hydroxybenzoate anion and a bridging water molecule that is also bound to the central Na + ion. The equatorial donor atoms form two trans chelate rings about each Mn III ion. A five-membered chelate ring is comprised of an oxime oxygen atom and a carbonyl oxygen atom from a shi 3À ligand, and a six-membered chelate ring is formed by an oxime nitrogen atom and a phenolate oxygen atom from a different shi 3À ligand.
The central Dy III ion on the convex side of the MC is eightcoordinate, with a distorted square antiprismatic geometry (CShM values: 0.550 for 1 and 0.818 for 2; Table 3; Casanova et al., 2005). Two different planes of oxygen atoms complete the coordination sphere. One plane is composed of four oxime oxygen atoms from the MC cavity, while the second plane is formed from four carboxylate oxygen atoms from either the 3-hydroxybenzoate or 4-hydroxybenzoate anions. The Dy III lies closer to the mean plane of carboxylate oxygen atoms [1.055 (3) Å for 1 and 1.076 (7) Å for 2] than to the mean plane of oxime oxygen atoms [1.546 (3) Å for 1 and 1.593 (7) Å for 2], indicating that the geometry is distorted from an ideal square antiprism geometry. The mean plane distances were calculated with SHELXL2018/3 (Sheldrick, 2015) and determined as previously described (Azar et al., 2014   The Na + ion captured on the concave side of the MC is also eight-coordinate; however, the geometry assignment is not clearly defined based on CShM values (Table 3). The CShM analysis slightly favors a biaugmented trigonalprismatic assignment (CShM values: 3.002 for 1 and 3.196 for 2); however, a square-antiprismatic geometry assignment is comparable (CShM values: 3.063 for 1 and 3.657 for 2). Both values are above 3.0; thus, there are substantial distortions from each ideal geometry. The biaugmented trigonal-prismatic geometry is a trigonal prism capped on two of the three rectangular faces. As for the Dy III ion, the Na + ion is surrounded by two groups of oxygen atoms. One group of oxygen atoms is formed from the oxime oxygen atoms of the MC cavity, and the second group is comprised of four oxygen atoms from water molecules. The Na + ion is positioned closer to the mean plane of water oxygen atoms [0.677 (5) Å for 1 and 0.561 (9) Å for 2] than to the mean plane of the oxime oxygen atoms [1.922 (4) Å for 1 and 1.991 (9) Å for 2].
Lastly, in both 1 and 2 solvent molecules are located in the structure, which are also hydrogen bonded to their respective MCs (described in the Supramolecular features section). For 1, the DMA molecules associated with N2 and N3 are disordered over two positions with occupancy ratios that refined to 0.496 (8):0.504 (8) and 0.608 (9):0.392 (9), respectively. The DMA molecule associated with N4 is disordered over four positions with occupancy ratios that refined to 2Â0.275 (7): 2Â0.225 (7). For 2, two DMF molecules associated with N6 and N7 are not disordered, while the two DMF molecules associated with N5 and N8 are disordered over two different orientations, which refined to 0.64 (3):0.36 (3) and 0.51 (2):0.49 (2), respectively. Complete details describing the treatment of the solvent disorder are given in the Refinement section.

Supramolecular features
For both 1 and 2 the solvent molecules form hydrogen bonds with the MC complexes. For 1, the MC complex forms hydrogen bonds to the DMA molecules, and the MCs are interconnected via the DMA molecules (Table 4). The hydroxyl group (O6) of each 3-hydroxybenzoate forms a hydrogen bond to the carbonyl oxygen atom (O9 i ) of a DMA molecule [ Fig. 3; symmetry code: (i) x, y, z À 1]. In addition, the water molecule (O7) coordinated to the central Na + ion hydrogen bonds to the carbonyl oxygen atoms (O8 and O8 ii ) of two DMA molecules [ Fig. 4; symmetry code: (ii) Àx + 3 2 , y, z]. Then, the methyl group (associated with C17) of the same DMA molecules forms a C-HÁ Á ÁO interaction with the hydroxyl group (O6 iii ) of a 3-hydroxybenzoate of a neighboring MC [symmetry code: (iii) Àx + 2, y À 1 2 , Àz + 1]. These interactions are repeated about the fourfold axis of the MC; thus, a network is generated between neighboring MCs mediated by the DMA molecule associated with N2. The connection between the neighboring MCs, the hydrogen bonds between the MCs and the DMA molecules, and pure van der Waals forces contribute to the overall packing of the molecules.

Figure 4
Intermolecular hydrogen bonding between the water molecule coordinated to the Na + ion of 1 and the DMA molecules. The DMA molecules then form C-HÁ Á ÁO interactions with the hydroxyl groups of 3hydroxybenzoate anions of neighboring MCs to generate a network between the complexes. For clarity only the hydrogen atoms (white) involved in the interactions have been included, and only the atoms involved in the interactions have been labeled. See Fig. 1 for additional display details. [Symmetry codes: (ii) y, Àx + 3 2 , z; (iii) y À 1 2 , Àx + 2, Àz + 1.]

Figure 3
Intermolecular hydrogen bonding between 1 and the carbonyl oxygen atom of a DMA molecule. For clarity only the hydrogen atoms (white) involved in the interactions have been included, and only the atoms involved in the interactions have been labeled. See Fig. 1 for additional display details. [Symmetry code: (i) x, y, z À 1.] bond between one of the water molecules (O25) coordinated to the Na + ion and a phenolate oxygen atom (O12) of the metallacrown (Fig. 5c). In addition, several hydrogen bonds exist between neighboring metallacrowns (Fig. 6). The hydrogen bonding occurs via the 4-hydroxybenzoate ligands. The hydroxyl group (O15) of a 4-hydroxybenzoate anion forms a hydrogen bond to O3 i (a phenolate oxygen atom of a shi 3À ligand) of a neighboring MC through two hydrogen bonds: O15-H15OÁ Á ÁO3 i and C32-H32Á Á ÁO3 i [symmetry code: (i) x À 1 2 , Ày + 1, z + 1 2 ]. The hydroxyl group (O21) of a 4-hydroxybenzoate anion also forms a hydrogen bond to a second MC via two hydrogen bonds: O21-H21OÁ Á ÁO22 ii (a 4-hydroxybenzoate carboxylate oxygen atom) and C46-H46Á Á ÁO9 ii [a phenolate oxygen atom of a shi 3À ligand; symmetry code: (ii) x À 1 2 , Ày + 2, z À 1 2 ]. Lastly, the hydroxyl group (O24) of a 4-hydroxybenzoate anion forms a hydrogen bond to a third MC via the hydrogen bond O24-H24OÁ Á ÁO6 iii [a phenolate oxygen atom of a shi 3À ligand; symmetry code: (iii) x À 1 2 , Ày + 2, z + 1 2 ]. Since each MC then forms reciprocal hydrogen bonds, each MC is hydrogen bonded to six neighboring MCs, forming a network of MCs. The hydrogen bonding between the neighboring MCs, between the MCs and the DMF molecules, and pure van der Waals forces contribute to the overall packing of the molecules. Intermolecular hydrogen bonding between the water molecules coordinated to the Na + ion of 2 and the DMF molecules and intramolecular hydrogen bonding between a water molecule coordinated to the Na + ion and a phenolate oxygen atom of the metallacrown. For clarity the hydrogen bonding has been divided into three sections (a), (b) and (c), only the hydrogen atoms (white) involved in the hydrogen bonding have been included, and only the atoms involved in the hydrogen bonding have been labeled. See Fig. 1 for additional display details. (ii) x À 1 2 ; Ày þ 2; z À 1 2 ; (iii) x À 1 2 ; Ày þ 2; z þ 1 2 .
As complexes 1 and 2 contain a sodium cation, the discussion will be limited to the [12-MC Mn(III)N(shi) -4] complexes 3-6 that also capture a dysprosium and a sodium cation in the central cavity. The use of 3-hydroxybenzoate and 4-hydroxybenzoate does not significantly alter the overall MC framework as a structural comparison of complexes 1-6 reveals that the metrical parameters of the structures are similar (Table 6). These features were measured and calculated using the program Mercury (Macrae et al., 2020) and in the same fashion as previously described (Azar et al., 2014). For 1 and 2, all metrical values fall within the range of 3-6. In addition, 1 and 2 are domed in a similar fashion as 3-6 with the average distance of the ring Mn III ions above their equatorial plane being 0.14 Å for both 1 and 2, which is consistent with the values for 3-6. Overall the molecular structure of the six complexes are analogous with only differing bridging carboxylate anions.
Synthesis of Dy III Na(3-OHben) 4 [12-MC Mn(III)N(shi) -4](H 2 O) 4 Á10DMA, 1. Manganese(II) acetate tetrahydrate (2 mmol, 0.4912 g) was dissolved in 8 mL of DMA, resulting in a clear orange solution. In a separate beaker, dysprosium(III) nitrate pentahydrate (0.250 mmol, 0.1108 g) and salicylhydroxamic acid (2 mmol, 0.3070 g) were dissolved in 8 mL of DMA, resulting in a clear and colorless solution. In another beaker, sodium 3-hydroxybenzoate (4 mmol, 0.6413 g) was mixed in 8 mL of DMA, resulting in an opaque yellow mixture as not all of the reagent dissolved. Then the manganese(II) acetate solution was added to the Dy(NO 3 ) 3 /H 3 shi solution, resulting in a dark-brown solution. Following, the sodium 3-hydroxybenzoate solution was added to the former solution and no color change was observed. The solution was stirred overnight and filtered the next day. A brown precipitate and clear and colorless solid were recovered and discarded. The filtrate was a dark-brown solution. Slow evaporation of the filtrate at room temperature afforded X-ray quality black/ dark-brown block-shaped crystals after six days. The percentage yield was 44% based on dysprosium(III) nitrate pentahydrate.
Synthesis of Dy III Na(4-OHben) 4 [12-MC Mn(III)N(shi) -4]-(H 2 O) 4 Á4DMF, 2. Manganese(II) acetate tetrahydrate (2 mmol, 0.4904 g) was dissolved in a solvent mixture of 5 mL of DMF and 5 mL of methanol, resulting in a clear orange solution. In a separate beaker, dysprosium(III) nitrate pentahydrate (0.250 mmol, 0.1099 g), sodium 4-hydroxybenzoate (4 mmol, 0.6411 g), and salicylhydroxamic acid (2 mmol, 0.3072 g) were mixed in a solvent mixture of 5 mL of DMF and 5 mL of methanol, and the resulting mixture had an opaque white color as not all of the reagents had dissolved. Then the manganese(II) acetate solution was added to the latter mixture, resulting in an opaque green solution. The  solution was stirred overnight and filtered the next day. A green precipitate was recovered and discarded. The filtrate was a dark green-brown solution. Slow evaporation of the filtrate at room temperature afforded X-ray quality black/ dark-brown block-shaped crystals after three weeks. The percentage yield was 56% based on dysprosium(III) nitrate pentahydrate.

Refinement
For 1, whole molecule disorder is observed for the main molecule, excluding only the Dy and Na ions. Equivalent disordered organic moieties were restrained to have similar geometries (SAME command of SHELXL), and U ij components of ADPs for all disordered atoms closer to each other than 2.0 Å were restrained to be similar (SIMU command of SHELXL). Subject to these conditions, the occupancy ratio refined to 0.8018 (14): 0.1982 (14). Three DMA molecules were refined as disordered. The two DMA molecules associated with N2 and N3 are in general positions by an approximate 180 rotation. The third DMA molecule associated with N4 is disordered by an exact 180 rotation from a twofold axis that bisects it as well as by additional general disorder. All DMA moieties were restrained to have similar geometries (SAME command of SHELXL). All N-CH 3 bond lengths were restrained to be similar in length and all 1,3 distances of the C-N-CH 3 angles were also restrained to be similar to each other. U ij components of ADPs for all DMA atoms closer to each other than 2.0 Å were restrained to be similar, and the atoms of the fourfold-disordered molecule were restrained to be close to isotropic. The lowest occupancy DMA molecule (the minor component disordered by twofold symmetry) was restrained to be close to planar. Subject to these conditions the occupancy ratios of the DMA molecules associated with N2, N3, and N4 refined to 0.496 (8):0.504 (8), 0.608 (9):0.392 (9), and 2Â0.275 (7):2Â0.225 (7), respectively. Initially alcohol hydrogen atoms were allowed to rotate about their respective oxygen atoms, and water hydrogen-atom positions were refined while a damping factor was applied, and O-H and HÁ Á ÁH distances were restrained to 0.84 (2) and 1.36 (2) Å , respectively. Some water hydrogen-atom positions were further restrained based on hydrogen-bonding considerations. In the final refinement cycles these hydrogen atoms were set to ride on their carrier oxygen atoms and the damping factor was removed. Additional crystal data, data collection, and structure refinement details are summarized in Table 7. For 2 the crystal under investigation was found to be a nonmerohedric twin. The orientation matrices for the two   components were identified using the program CELL_NOW (Sheldrick, 2008b), with the two components being related by a 90 rotation around the real a axis. The two components were integrated using SAINT (Bruker, 2018) and corrected for absorption using TWINABS (Sheldrick, 2012). The twin matrix obtained by the integration program was (1 0 0 0 0 1 0 À 1 0). The structure was solved by direct methods with only the non-overlapping reflections of component 1. The structure was refined using all reflections of component 1 (including overlaps), resulting in a minor-component fraction of 0.0818 (8). The R int value given is for all reflections and is based on agreement between observed single and composite intensities and those calculated from refined unique intensities and twin fractions (TWINABS; Sheldrick 2012). Sections of the metallacrown are disordered including the Dy ion, Mn1, two of the 4-hydroxybenzoate ligands bound to Mn1 and Mn2, the salicylhydroximate ligand that connects Mn1 and Mn4, and portions of the remaining three salicylhydroximate ligands. The major moiety 4-hydroxybenzoate anion geometry was restrained to be similar to that of a non-disordered 4-hydroxybenzoate. The geometry of the entire minor moiety was restrained to be similar to that of the major moiety. Some sections of the minor disordered salicylhydroximate ligands were restrained to be planar. Pairs of close to overlapping equivalent atoms of the major and minor moieties were constrained to have identical ADPs (C1 and C1B, N2 and N2B, O4 and O4B, O7 and O7B, C22 and C22B, Dy1 and Dy1B). Two solvate DMF molecules are disordered over different orientations. The major and minor disordered moieties were each restrained to have similar geometries. U ij components of ADPs for all disordered atoms closer to each other than 2.0 Å were restrained to be similar. Subject to these conditions the occupancy ratio for the main molecule disorder refined to 0.849 (9):0.151 (9). The disorder of the two DMF moieties refined to 0.64 (3):0.36 (3) for the DMF associated with N5 and to 0.51 (2):0.49 (2) for the DMF molecule associated with N8. Water hydrogen atom positions were refined and O-H and HÁ Á ÁH distances were restrained to 0.84 (2) and 1.36 (2) Å , respectively. Some water hydrogen-atom positions were further restrained based on hydrogen-bonding considerations and were restrained to be at least 3.10 (2) Å from the sodium ion. Additional crystal data, data collection, and structure refinement details are summarized in Table 7. For both structures, data collection: APEX3 (Bruker, 2018); cell refinement: SAINT (Bruker, 2018); data reduction:

Special details
Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds involving l.s. planes. Refinement. Whole molecule disorder is observed for the main molecule, excluding only the Dy and Na ions. Equivalent disordered organic moieties were restrained to have similar geometries, and Uij components of ADPs for all disordered atoms closer to each other than 2.0 Angstrom were restrained to be similar. Subject to these conditions the occupancy ratio refined to 0.8018 (14) to 0.1982 (14). Three DMA molecules were refined as disordered. Two in general positions by an approximate 180 degree rotation. The third is in addition also disordered by an exact 180 degree rotation from a two fold axis that bisects it. All DMA moieties were restrained to have similar geometries SAME command of Shelxl). All N-CH3 bond lengths were restrained to be similar to each other, and all 1,3 distances of the C-N-CH3 angles were also restrained to be similar. Uij components of ADPs for all DMA atoms closer to each other than 2.0 Angstrom were restrained to be similar, and the atoms of the four fold disordered molecule were restrained to be close to isotropic. The least occupied DMA molecule (the minor component disordered by two fold symmetry) was restrained to be close to planar. Subject to these conditions the occupancy ratios refined to 0.496 (8) to 0.504 (8), 0.608 (9) to 0.392 (9), and two times 0.275 (7) to two times 0.225 (7). Alcohol H atoms were initially allowed to rotate and Water H atom positions were initially refined while a damping factor was applied and O-H and H···H distances were restrained to 0.84 (2) and 1.36 (2) Angstrom, respectively. Some water H atom positions were further restrained based on hydrogen bonding considerations. In the final refinement cycles these H atoms were set to ride on their carrier oxygen atoms and the damping factor was removed.