Structures with high Z'
The table below contains details of all the structures with Z' >= 12 in the Cambridge Structural Database. As well as the name, journal reference and CSD Refcode there is a "Notes" section for each structure noting anything of interest about the packing or composition of the asymmetric unit, as well as links to polymorphs, redeterminations or similar structures. If you have anything to add or spot any errors then please let us know.
| Z' | Compound name |
Notes |
Reference |
Refcode |
Year |
|---|---|---|---|---|---|
| 12 |
trans-13-Azabicyclo(10.2.0)tetradecan-14-one |
No 3D coordinates. Authors note that the structure was indexed in an orthorhombic cell but has been refined in P1 |
L. Fabian, A. Kalman, G. Argay, G. Bernath, Z. Cs. Gyarmati, Chem. Commun., 2004, 2114 | ABUDAD02 | 2004 |
| 12 |
Cyclopropanecarboxylic acid isonicotinamide |
Centrosymmetric isonicotinamide dimers terminated by hydrogen bonding to the cyclopropane carboxylic acid. The cyclopropyl group renders the assembly non-planar and imparts a dumbell shape. The high Z' seems to arise from the stacking of these dumbells in such a way as to accomodate the cycloproply substituents. The 'awkward' shape of the assembly is reminiscent of the 'wheel-and-axel' host design paradigm. |
A. Lemmerer, M. A. Fernandes, New J. Chem., 2012, 36, 2242 | ACOMOW | 2012 |
| 12 |
5-((t-butyl(dimethyl)silyl)oxy)-4-ethynyl-4-(1-fluorohexyl)-1,2,3-oxathiazepane 2,2-dioxide |
Partial ordering of the positional disorder of a high temperature phase to give a low temperature phase with Z′ = 12. Sulfonamide hydrogen bonding. |
A.I.Vinokur, A.Yakovenko, Lu Liu, J.M.Schomaker, I.A.Guzei, Cryst.Growth Des., 2017, 17, 5984 | ADUNOF01 | 2017 |
| 12 |
bis(η5-Pentamethylcyclopentadienyl)-iron trifluoromethanesulfonate |
Superstructure low temperature phase in P1 derived from high symmetry Z' = 0.5 high temperature form in Pmn21. The authors state that "the superstructure originates from the different conformers of the cations and canting of the OTf anions. The conformational differences among the cations as well as the polar orientation of the anion resulted in the non-centrosymmetric space group." |
S. Hamada, Y. Funasako, T. Mochida, D. Kuwahara, K. Yoza, J. Organomet. Chem., 2012, 713, 35 | DECYAN01 | 2012 |
| 12 |
4-(3,5-dichlorophenyl)-1,2,3,5-dithiadiazolyl radical |
cis-cofacial π*–π* dimers with intra-dimer S⋯S contacts in the range 3.1–3.3 Å. |
C.P.Constantinides, D.J.Eisler, A.Alberola, E.Carter, D.M.Murphy, J.M.Rawson, CrystEngComm, 2014, 16, 7298 | DIXNEF | 2014 |
| 12 |
(N-t-butylcyano)-chloro-(2-(pyridin-2-yl)phenyl)-platinum |
Stacked Pt…Pt dimers with falt and bulky regions. The paper referenced concerns trans-[Co(NCNMe2)2(H2O)4]X2 2H2O. Error? |
E.V.Andrusenko, A.S.Novikov, G.L.Starova, N.A.Bokach, Inorg.Chim.Acta, 2016, 447, 142 | EYONEN | 2016 |
| 12 |
4-Ethynyl-N,N-dimethylaniline |
High temperature alpha polymorph |
A. S. Batsanov, J. C. Collings, R. M. Ward, A. E. Goeta, L. Porres, A. Beeby, J. A. K. Howard, J. W. Steed, T. B. Marder, CrystEngComm, 2006, 8, 622 | GENLAN | 2006 |
| 12 |
4-Ethynyl-N,N-dimethylaniline |
Low temperature beta polymorph |
A. S. Batsanov, J. C. Collings, R. M. Ward, A. E. Goeta, L. Porres, A. Beeby, J. A. K. Howard, J. W. Steed, T. B. Marder, CrystEngComm, 2006, 8, 622 | GENLAN01 | 2006 |
| 12 |
Triphenylmethanaminium anthracene-2-sulfonate mesitylene solvate |
A salt with included mesitylene with a porous diamondoid architecture, exhibiting small distortions in the π-π stacking arrangement. |
A. Yamamoto, S. Uehara, T. Hamada, M. Miyata, I. Hisaki, N. Tohnai, Cryst. Growth Des., 2012, 12, 4600 | HEBGOM | 2012 |
| 12 |
Triphenylmethanaminium anthracene-2-sulfonate mesitylene solvate |
See HEBGOM |
A. Yamamoto, S. Uehara, T. Hamada, M. Miyata, I. Hisaki, N. Tohnai, Cryst. Growth Des., 2012, 12, 4600 | HEBGOM01 | 2012 |
| 12 |
Triphenylmethanaminium anthracene-2-sulfonate mesitylene solvate |
See HEBGOM |
A. Yamamoto, T. Hamada, I. Hisaki, M. Miyata, N. Tohnai, Angew. Chem., Int. Ed., 2013, 52, 1709 | HEBGOM02 | 2013 |
| 12 |
4,4-Diphenyl-2,5-cyclohexadienone |
Z' = 2 (HEYHUO03) and Z' = 4 (HEYHUO01) polymorphs also known |
V. S. S. Kumar, A. Addlagatta, A. Nangia, W. T. Robinson, C. K. Broder, R. Mondal, I. R. Evans, J. A. K. Howard, F. H. Allen, Angew. Chem., Int. Ed., 2002, 41, 3848 | HEYHUO02 | 2002 |
| 12 |
7-(4-isopropylphenyl)-2-oxo-3,5,6,7-tetrahydro-2H-thiopyrano[2,3-d][1,3]thiazole-6-carbaldehyde |
Tilted / modulated hydrogen bonded chain, rigid molecule. |
A.Lozynskyi, S.Golota, B.Zimenkovsky, D.Atamanyuk, A.Gzella, R.Lesyk, Phosphorus,Sulfur,Silicon,Relat.Elem., 2016, 191, 1245 | IVUBUY | 2016 |
| 12 |
bis(4-(pyrrolidin-1-yl)pyridine)-silver nitrate hemihydrate |
Cylindrical arrangement with half of the nitrates bridging between cylinders, and disordered water and the remaining nitrate ions inside the cylinders. The authors provide an interesting analysis in which the structure is described as intertwined three-connected networks, as each silver complex connects to two other complexes through –CH2–CH2–⋯–CH2–CH2– “embraces” and to one other complex through bridging nitrate anions. The topology of these 3D-nets is the common srs net (the (10,3)-a (Wells) or SrSi2 net. |
M.A.M.Abu-Youssef, S.M.Soliman, M.M.Sharaf, J.H.Albering, L.Ohrstrom, CrystEngComm, 2016, 18, 1883 | LALZIK | 2016 |
| 12 |
N,N'-bis(n-Butyl)-1H-pyrrole-2,5-dithiocarboxamide |
Low temperature form. Undergoes phase transition at 195.8 K to Z' = 1 form (LANXOO) |
L. Dobrzycki, T. Zielinski, J. Jurczak, K. Wozniak, J. Phys. Org. Chem., 2005, 18, 864 | LANXOO02 | 2005 |
| 12 |
1-(cyclohex-2-en-1-yl(hydroxy)methyl)-4-hexyl-5-methyl-6-oxa-2-azabicyclo[3.2.0]heptane-3,7-dione |
Independent molecules are conformationally different |
M. Stadler, J. Bitzer, A. Mayer-Bartschmid, H. Muller, J. Benet-Buchholz, F. Gantner, H. -V. Tichy, P. Reinemer, K. B. Bacon, J. Nat. Prod., 2007, 70, 246 | LEZQUD | 2007 |
| 12 |
6-cyclohexyl-1-hydroxy-4-methylpyridin-2(1H)-one |
Pharmaceutical Ciclopirox. There are Z' = 12 and Z' = 1 forms along with kinetic, transient intermediate disordered forms. The reversible transitions involve a subtle compromise between phenomena related to molecular disorder, cooperative release of strains induced by cooling, and structural reorganization associated with topotactic changes in crystal lattice and symmetry. |
C.Brandel, Y.Cartigny, N.Couvrat, M.Ermelinda S.Eusebio, Joao Canotilho, S.Petit, G.Coquerel, Chem.Mater., 2015, 27, 6360 | LUXYOU | 2015 |
| 12 |
(N,N-bis(1-phenylethyl)-16,22-bis(1,1':3',1''-terphenyl-5'-yl)-18,20-dioxa-19-phosphahexacyclo[19.2.2.2$14,17!.0$2,7!.0$6,9!.0$8,13!]heptacosa-1(23),2,4,6,8,10,12,14,16,21,24,26-dodecaen-19-amine)-chloro-gold heptane solvate |
No 3D coordinates and the structure is not discussed in the paper. |
Zhiyong Wu, K.Isaac, P.Retailleau, J.-F.Betzer, A.Voituriez, A.Marinetti, Chem.-Eur.J., 2016, 22, 3278 | NAHBEG | 2016 |
| 12 |
4-(But-3-en-1-ylamino)-3-nitrobenzoic acid |
Planar centrosymmetric dimers with a non-planar tail that stack in an offset fashion. |
S. N. Narendra Babu, A. S. Abdul Rahim, H. Osman, S. R. Jebas, H. -K. Fun, Acta Crystallogr., Sect. E: Struct. Rep. Online, 2009, 65, o1560 | POWLOD | 2009 |
| 12 |
Diphenylphosphanyl(trimethylsilyl)imine |
PLATON suggests an alternative space group, Pn21a with Z' = 6 (see Brock et al., Acta Cryst B., 2005, B61, 218) |
S. Wingerter, M. Pfeiffer, F. Baier, T. Stey, D. Stalke, Z. Anorg. Allg. Chem., 2000, 626, 1121 | QAJDAG | 2000 |
| 12 |
6'-Methoxy-10-methyl-10,11-dihydrocinchonan-9-ol benzene solvate monohydrate |
Complex solvate. Molecule has flat and bulky regions. Not discussed in the paper. |
H.T.Dao, Chao Li, Q.Michaudel, B.D.Maxwell, P.S.Baran, J.Am.Chem.Soc., 2015, 137, 8046 | RUKTOI | 2015 |
| 12 |
4,8,12,14,14-pentamethyl-13-oxabicyclo[10.2.2]hexadeca-4,8-dien-16-ol |
Cyclic tetramers of a bulky secondary alcohol, consistent with the work of Brock and Duncan, Chem. Mater., 1994, 6, 1307. |
M.P.Rahelivao, M.Gruner, T.Lubken, D.Islamov, O.Kataeva, H.Andriamanantoanina, I.Bauer, H.-J.Knolker, Org.Biomol.Chem., 2016, 14, 989 | RUYZES | 2016 |
| 12 |
2-(iodoethynyl)pyridine |
Chun-Fai Ng, Hak-Fun Chow, T.C.W.Mak, Angew.Chem.,Int.Ed., 2018, 57, 4986 | SEVSUK01 | 2018 | |
| 12 |
2,3-diphenylacrylic acid propan-2-ol solvate |
Solvate based on bulky carboxylic acid dimers. Not discussed in the publication. |
Xueqiang Wang, M.Nakajima, R.Martin, J.Am.Chem.Soc., 2015, 137, 8924 | SUPWUX | 2015 |
| 12 |
(2,6-bis((diisopropylphosphino)methyl)-4-hydroxyphenyl)-dicarbonyl-hydrido-iron |
Rigid structure with two hydrogen bonded phenol-derived coordination complex hexameric superstructures |
A.Dauth, U.Gellrich, Y.Diskin-Posner, Y.Ben-David, D.Milstein, J.Am.Chem.Soc., 2017, 139, 2799 | TAYVAT | 2017 |
| 12 |
Trimesic acid hydrate |
Trimesic acid acts as host and guest. The length of a pair of trimesic acid guests corresponds to five layers of the trimesic acid hydrate host hence the structure can be formulated as two repeats of {(C9H6O6).H2O}5.C9H6O6.} |
F. H. Herbstein, R. E. Marsh, Acta Crystallogr., Sect. B: Struct. Crystallogr. Cryst. Chem., 1977, 33, 2358 | TRIMES10 | 1977 |
| 12 |
ammonium 5,5-dimethoxy-1,3,2-dioxaphosphinan-2-olate 2-oxide |
Four polymorphs with Z' = 12, 6, 6 and 1. Chair - skew ring flipping, which takes place during single crystal to single crystal phase transitions, results in various populations of skew and chair conformers in different phases. |
K.A.Slepokura, Acta Crystallogr.,Sect.B:Struct.Sci.,Cryst.Eng. and Mat., 2016, 72, 117 | VIVSAV02 | 2016 |
| 12 |
2,4,6-Trinitro-1-bromobenzene |
δ polymorph For other polymorphs see ZZZVXQ03, ZZZVXQ05 and ZZZVXQ06 |
D. A. Parrish, J. R. Deschamps, R. D. Gilardi, R. J. Butcher, Cryst. Growth Des., 2008, 8, 57 | ZZZVXQ02 | 2008 |
| 12 |
2,4,6-Trinitro-1-bromobenzene |
γ polymorph. For other polymorphs see ZZZVXQ02, ZZZVXQ03 and ZZZVXQ06 |
D. A. Parrish, J. R. Deschamps, R. D. Gilardi, R. J. Butcher, Cryst. Growth Des., 2008, 8, 57 | ZZZVXQ05 | 2008 |
| 13 |
catena-[bis((mu-5-methylbenzimidazolyl)-(mu-5-bromobenzimidazolyl))-zinc(ii) unknown solvate] |
Complex ZIF coordination polymer |
Jingjing Yang, Yue-Biao Zhang, Qi Liu, C.A.Trickett, E.Gutierrez-Puebla, M.Angeles Monge, Hengjiang Cong, A.Aldossary, Hexiang Deng, O.M.Yaghi, J.Am.Chem.Soc., 2017, 139, 6448 | NEHKUJ | 2017 |
| 14 |
4-(4-ethoxy-2,3,5,6-tetrafluorophenyl)-3H-1,2,3,5-dithiadiazol-3-yl radical |
Radical interaction, gamma polymorph of GEQLUM05 from subimation |
Y.Beldjoudi, Rui Sun, A.Arauzo, J.Campo, R.J.Less, J.M.Rawson, Cryst.Growth Des., 2017, 18, 179 | GEQLUM04 | 2017 |
| 14 |
1,3,5-tris(4-Carboxyphenyl)benzene unknown solvate |
Similar stacking arrangement to OGUROZ |
C.A.Zentner, H.W.H.Lai, J.T.Greenfield, R.A.Wiscons, M.Zeller, C.F.Campana, O.Talu, S.A.FitzGerald, J.L.C.Rowsell, Chem.Commun., 2015, 51, 11642 | OGUROZ01 | 2015 |
| 15 |
pentadecakis(tris(mu2-4-Methylpyrazolato-N,N')-tri-gold(I)) dichloromethane hexane methanol solvate dihydrate |
The structure has a total of some 45 crystallographically unique gold(I) centres arranged into planar trimmers with significant Au...Au interactions, with each pair of gold(I) center bridged by a 4-methylpyrazolato anion. There are 15 crystallographically unique trimers with their packing dictated by further interplanar Au...Au interactions and the intercalation of the methyl substitutents within the concave groove of adjacent trimers to give offset stacks arranged not quite orthogonally. Based on reasonable aurophilic interactions Five gold trimers form independent units, while two exist as dimers of trimmers. An additional eight trimers, (with symmetry equivalents) constitute a 16-membered aggregate of trimers. In this way fairly close packing of the structure is achieved, with small lattice voids being occupied by a number of solvent molecules, namely a molecule of hexane, dichloromethane, methanol and two water molecules for every fifteen timeric complexes. The hexane is disordered. This unusual stoichiometry leads to a formal Z′ value of just 1, however a Z′ = 15 assignment has considerable justification and is arguably more useful. |
G. Yang and R. G. Raptis, Inorg. Chem., 2003, 42, 261 | MUTLAO | 2003 |
| 15 |
Sodium t-butoxide |
Later reinterpreted as Z' = 5 (NABUOX10) and Z' = 0.33 (NABUOX11) |
T. Greiser, E. Weiss, Chem. Ber., 1977, 110, 3388 | NABUOX | 1977 |
| 16 |
2,2-Aziridine-dicarboxamide |
Layer structure. Lower Z' polymorph known (BIPCOS, Z' = 4).For recent redetermination in P-1, Z' = 8 see BIPCOS02 |
S. Bruckner, Acta Crystallogr., Sect. B: Struct. Crystallogr. Cryst. Chem., 1982, 38, 2405 | BIPCOS01 | 1982 |
| 16 |
Cholesterol |
Other Z' = 16 (CHOEST21) and Z' = 8 (CHOEST02, CHOEST10, CHOEST20) polymorphs also known |
L. -Y. Hsu, C. E. Nordman, ACA, Ser. 2, 1981, 9, 35a | CHOEST01 | 1981 |
| 16 |
Cholesterol |
See CHOEST01 |
Leh-Yeh Hsu, J. W. Kampf, C. E. Nordman, Acta Crystallogr. ,Sect. B:Struct. Sci., 2002, 58, 260 | CHOEST21 | 2002 |
| 16 |
Cholesterol monohydrate |
Early reported structure of cholesterol monohydrate. See CHOLES20 for Z' = 8 form and discussion of pseudosymmetry (B. M. Craven, Acta Crystallogr., Sect. B, 1979, 35, 1123) . A Z' = 4 form (CHOLES05) was also reported in 1963 (H. Bogren, K. Larsson, Biochim. Biophys Acta 1963, 75, 65-69) suggesting that significant twinning may invalidate this Z' = 16 form. |
J. D. Bernal, Philos.Trans. R. Soc. London, Ser. A , 1940, 239, 135 | CHOLES03 | 1940 |
| 16 |
beta-Est-2C hydrate |
Protein-like β3 -peptide bundles possessing unique quaternary structures and catalytic activity. Active site triad composed of residues from at least two strands of the octameric bundle structure. |
P.S.P.Wang, J.B.Nguyen, A.Schepartz, J.Am.Chem.Soc., 2014, 136, 6810 | JIZFAB | 2014 |
| 16 |
Sodium 1,2-benzisothiazol-3(2H)-onate 1,1-dioxide hydrate |
Structure consists of "regular" and "irregular" regions held together by hydrogen bonds and Na···O interactions. The asymmetric unit contains 16 saccarinates (15 ordered and one disordered over two sites), 16 sodium ions (13 ordered and 3 disordered over two sites each) and 30 water molecules. 26 water molecules are ordered and all but one hydrogen atoms of these ordered water molecules were found from the Fourier map. The remaining four water molecules are disordered over two sites each. While the water oxygen atoms could be assigned with ease, only 1/4 of the hydrogen atoms could be found from the Fourier map.Also reported at same time by: P. Naumov, G. Jovanovski, O. Grupce, B. Kaitner, A. D. Rae, and S. W. Ng, Angew. Chem., Int. Ed., 2005, 44, 1251 |
R. Banerjee, P. M. Bhatt, M. T. Kirchner, G. R. Desiraju, Angew. Chem., Int. Ed., 2005, 44, 2515 | LANBOS | 2005 |
| 16 |
(15-Crown-5) triaqua-dichloro-dioxo-uranium |
Cocrystal with Z'' = 32 comprising hydrogen-bonded chains on uranyl aqua complexes and [15]crown-5. The directionality of the multiple hydrogen bonding interactions is apparently incompatible with a more symmetrical structure and the asymmetric unit comprises four separate hydrogen bonded chains, each with four independent repeat units. |
H. Hassaballa, J. W. Steed, P. C. Junk, Chem. Commun., 1998, 577 | NIKZUC | 1998 |
| 16 |
15-Crown-5 triaqua-dichloro-dioxo-uranium |
See NIKZUC for preliminary communication of this structure. |
H. Hassaballa, J. W. Steed, P. C. Junk, M. R. J. Elsegood, Inorg. Chem., 1998, 37, 4666 | NIKZUC01 | 1998 |
| 16 |
2,4,6,8,10,12-Hexanitro-2,4,6,8,10,12-hexa-azatetracyclo(5.5.0.03,11.05,9)dodecane |
No 3D coordinates reported. Cell length a is 102Å, structure is reported as Monoclinic ε polymorph therefore possibly there is an incorrect cell reported/determined? |
N. I. Golovina, A. V. Raevsky, N. V. Chukanov, B. L. Korsunsky, L. O. Atovmyan, S. M. Aldoshin, Ross. Khim. Zhurnal(Russ. )(Russ. Chem. J. ), 2004, 48, 41-1 | PUBMUU21 | 2004 |
| 16 |
Tricarbonyl-((1-4-eta)-6-exo-cyano-2-(phenylsulfonyl)-1,3-cyclohexadiene)-iron |
No 3D coordinates |
Shang-Shing P. Chou, Shih-Hsien Liu, J. Organomet. Chem., 1998, 555, 227 | PUTKOE | 1998 |
| 16 |
(2-(1-Aminoethyl)-5-methoxyphenyl)-chloro-(pyridine)-palladium |
The 16 independent molecules all differ in minor conformational respects. The compound also forms a solvate with acetonitrile with Z′ = 2. The existence of high Z′ forms and low Z′ solvates/cocrystals is a recurring theme and the two extremes represent alternative solutions to the molecular packing problem. There are a number of conformations of similar energy and the quasiracemic nature of the material may also be a contributing factors (however high Z′ structures tend to be formed by more rigid molecules). |
B. Braun, I. Kalf, U. Englert, Chem. Commun., 2011, 47, 3846 | UNADOD | 2011 |
| 16 |
4-(2,2,4-trimethyl-3,4-dihydro-2H-1-benzothiopyran-4-yl)phenol isopropanol solvate |
Molecule with flat and bulky sections. Isostructural with Se analogue VANJAY. |
C.S.Frampton, K.K.Ketuly, H.B.M.Ali, A.H.S.Azizan, J.H.Gall, D.D.MacNicol, CrystEngComm, 2017, 19, 2653 | VANFUO | 2017 |
| 16 |
4-(2,2,4-trimethyl-3,4-dihydro-2H-1-benzoselenopyran-4-yl)phenol isopropanol solvate |
Molecule with flat and bulky sections. Isostructural with sulfur analogue VANFUO. |
C.S.Frampton, K.K.Ketuly, H.B.M.Ali, A.H.S.Azizan, J.H.Gall, D.D.MacNicol, CrystEngComm, 2017, 19, 2653 | VANJAY | 2017 |
| 18 |
(bis(tris(t-Butoxy)silyloxy)boryloxy)-bis(?5-cyclopentadienyl)-methyl-zirconium |
Each molecule in asymmetric unit has a unique conformation or orientation. |
K. L. Fujdala, A. G. Oliver, F. J. Hollander, T. D. Tilley, Inorg. Chem., 2003, 42, 1140 | HUVLAL | 2003 |
| 18 |
N-[2-(1,1-dimethylsiletan-3-yl)-2-(3-fluorophenyl)ethyl]methanesulfonamide |
Z.J.Garlets, H.M.L.Davies, Org.Lett., 2018, 20, 2168 | KETTUB | 2018 | |
| 18 |
2,4,6-Trinitro-1-bromobenzene |
ε polymorph. For other polymorphs see ZZZVXQ02, ZZZVXQ03 and ZZZVXQ05. All forms have Z′ values of three or more. All of the structures have a common “triad” motif, consisting of C-H...O hydrogen bonds and N-O...Br dipole-induced interactions. The differences between the polymorphs comes down to the orientation of sheet-to-sheet alignments. All five polymorphs were isolated concomitantly from the same vial provided by the Naval Surface Warfare Center and subsequent attempts to repeat the crystallization have only resulted in the Z′=3 alpha-form, suggesting perhaps a role of impurities in influencing the polymorphic outcome. |
D. A. Parrish, J. R. Deschamps, R. D. Gilardi, R. J. Butcher, Cryst. Growth Des., 2008, 8, 57 | ZZZVXQ06 | 2008 |
| 19 |
Poly((S),(R)-5-methyl-1-heptene) |
No 3D coordinates. Polymer. The Z' value relates to covalent monomers within a repeat of the covalent polymer strand. |
P. Corradini, E. Martuscelli, G. Montagnoli, V. Petraccone, Eur. Polym. J., 1970, 6, 1201 | HUGDOC | 1970 |
| 20 |
N'-(2-(4-Bromophenyl)-2-vinylcyclobutylidene)-4-methylbenzenesulfonohydrazide |
Resolved chiral substance in P1. The sulfonamide groups are linked together by an 8-membered hydrogen bonded ring twisted slightly out of planarity by steric demands and by the formation of a bifurcated donor interaction to an additional molecule. There are also CH···pi interactions and some disorder of the vinyl group. Very minor conformational variations suggest that the optimization of hydrogen bonding and close packing considerations is a starting place to explain the very high Z′ value. |
F. Kleinbeck, F. D. Toste, J. Am. Chem. Soc., 2009, 131, 9178 | VUJBAE | 2009 |
| 20.5 |
(1R,6R,10R,11S,12R)-6-Acetoxy-10,12,16-trihydroxydolaballa-3Z,7E-diene |
Likely to be significant errors in the original paper regarding unit cell length and crystal class. Z' is likely to be either 1 or 1.5. |
T. Hashimoto, M. Toyota, H. Koyama, A. Kikkawa, M. Yoshida, M. Tanaka, S. Takaoka, Y. Asakawa, Tetrahedron Lett., 1998, 39, 579 | BEWZEI | 1998 |
| 24 |
(η2,η2-cyclo-octa-1,5-diene)-((S)-2-(1,1-diphenylethyl)-4-(2-(bis(2-methylphenyl)phosphino)ethyl)oxazoline-N,P)-iridium tetrakis(3,5-bis(trifluoromethyl)phenyl)borate |
The structure is not discussed in the original publication but the authors report that the unit cell can be reduced to a higher symmetry Z′ = 1 sub-cell. This description does not account for some relatively weak interlayer reflections that give rise to the much higher Z′ supercell and it is likely that the structure is an incommensurately modulated version of the high symmetry structure. |
D.-R. Hou, J. Reibenspies, T. J. Colacot, K. Burgess, Chem. Eur. J., 2001, 7, 5391 | IDOSID | 2001 |
| 24 |
bis-(N-(2,6-bis(pyrazol-1-yl)pyrid-4-yl)acetamide)-iron(ii) bis(tetrafluoroborate) acetone solvate |
The sample exhibits an abrupt, hysteretic spin-crossover at T½ = 137 K (ΔT½ = 14 K) that proceeds to ca 50 % completeness. This is associated with a crystallographic phase transition, from phase 1 (P21/c, Z' = 1) to phase 2 (P21, Z' = 24). |
I.C.Berdiell, R.Kulmaczewski, O.Cespedes, M.A.Halcrow, Chem.-Eur.J., 2018, 24, 5055 | VIFXEQ | 2018 |
| 32 |
Trimethyl-tin hydroxide |
83 helical superstructure arising from short Sn···O interactions. No 3D coordinates but the published paper contains a careful study on possible sub-cells. A reinvestigation has been published including a P21/c low temperature pahse with Z' = 1: Cryst. Growth Des. 2011, 11, 820. A more recent reinvestigation finds a commensurately modulated P212121 structure for the low temperature phase consistent with the P212121 form in the CSD as a private communication (TMESNH01). Dey, S.; Schönleber, A.; Mondal, S.; van Smaalen, S. Superspace description of trimethyltin hydroxide at T = 100 K. Z. Krystallogr. 2016, 231, 427. The authors find no evidence for the P21/c form. In 2018 a reinvestigation of the Z' = 32 high temperature phase showed it to be Z' = 4 . Dey, S.; Schonleber, A.; Mondal, S.; Ali, S. I.; van Smaalen, S. Role of Steric Hindrance in the Crystal Packing of Z '=4 Superstructure of Trimethyltin Hydroxide. Cryst. Growth Des. 2018, 18, 1394. The earlier Z' = 32 determinations may be incorrect because "[s]tructured diffuse scattering observed at the positions of presumed superlattice reflections along a* and b* might have appeared as Bragg reflections". Alternatively, the Z' = 32 form could be different polymorph. It seems likely that the Z' = 4 superspace description is correct although it is noteworthy that the crystals in the latter publication were stored for an extended time at 250K. |
N. Kasai, K. Yasuda, R. Okawara, J. Organomet. Chem., 1965, 3, 172 | TMESNH | 1965 |
| 56 |
1,3,5-tris(4-Carboxyphenyl)benzene unknown solvate |
Z' world record holder. See also Z' = 14 polymorph OGUROZ01. 8-fold polycatenated assembly of (6,3) hexagonal nets formed through hydrogen bonds and π-stacking. The stack length seems to depend on the included solvent. |
C.A.Zentner, H.W.H.Lai, J.T.Greenfield, R.A.Wiscons, M.Zeller, C.F.Campana, O.Talu, S.A.FitzGerald, J.L.C.Rowsell, Chem.Commun., 2015, 51, 11642 | OGUROZ | 2015 |