Structure of 1-Methyl-5-(D-ga/acto-1 ,2,3,4,5-pentaacetoxypentyl)- 3-phenylpyrazole

1894 [KE(C4oH 6N 6)]-K AND [Cu(C40H 6N,6)]--Cu ~O~ __"'o--__ ~o'~ --0-- __0__ ]+, ~0 ~" -.--°°- -0- ::):::] o ..o-...**'o:'o H - -- -- ~O ~. --o_ ---a.--*-- ":/;09/ ~o'-. III III .~'..7.... ........ ",Q~" (a) (b) Fig. 11. Schema ic desc ip ion o epi axic g ow h o (a) he K2Pc(CN)8-K c ys al on a KC1 (001) su ace and (b) he MPc(CN)s-M c ys al on a me al ilm. complex ake a andom o ien a ion on he Cu ilm cons uc ed wi h a single c ys al and he e is no speci ic ela ion be ween he deposi and subs a e c ys als. Fig. 11 shows a schema ic desc ip ion o he epi- axic g ow h o he K2Pc(CN)8-K and MPc(CN)8-M complex c ys als on he subs a es. In he case o he K2Pc(CN)8-K c ys al on a KC1 (001) su ace, [K2Pc(CN)8] molecules make la con ac wi h he subs a e su ace owing o in e ac ion be ween hei cyan(> g oups and K ÷ ions on a KC1 su ace as shown in Fig. 1 l(a). Squa e la ices o he c ys als ake h ee di e en o ien a ions depending on mul i- ple posi ioning o [K2Pc(CN)8] molecules on he ionic la ice o he KC1 c ys al. Molecula columns o hese c ys als s and pe pendicula o he subs a e. In he case o he MPc(CN)8-M complex c ys al on a me al ilm, [MPc(CN)8] molecules come in o con ac wi h he subs a e su ace a di e en angles because he e is no aniso opic in e ac ion be ween he cyano g oups and he me al su ace. These c ys als do no show a speci ic mu ual o ien a ion wi h he subs a e c ys al and he molecula columns o he MPc(CN)8- M complex g ow in andom di ec ions. Re e ences ASmDA, M. (1966a). Bull. Chem. Soc. Jpn, 39, 2632-2638. ASm'DA, M. (1966b). Bull. Chem. Soc. Jpn, 39, 2625-2631. ASHIDA, M., UEDA, Y. & YANAGI, H. (1986). Bull. Chem. Soc. Jpn, 59, 1437-1441. ASHIDA, M., UEDA, Y., YANAGI H., FUJIYOSHI, Y., UYEDA, N. & FRYER, J. R. (1988). Ac a C ys . B44, 146-151. BAILEY, A. S., HENN, R. B. & LANGTON, J. M. (1963). Te a- hed on, 19, 161-167. BLODGETT, K. B. (1935). J. Am. Chem. Soc. 57, 1007-1022. GRINBERG, A. (1963). Phys. S a us Solidi, 32, 1369--1378. HATTORI, Y., ASHIDA, M. & WATANABE, T. (1975). Nippon Kagaku Kaishi, pp. 496-500. KOBAYASHI, H. (1961). Nippon Kagaku Zasshi, 82, 272-276. PROUT, C. K. • TICKLE, I. J. (1973). J. Chem. Soc. Pe kin T ans. 2, pp. 520-523. UEDA, Y. (1987). Bull. Chem. Soc. Jpn, 60, 2011-2017. UEDA, Y. & ASmDA, M. (1980). J. EleC on Mic osc. 29, 38-44. UYEDA, N., ASmDA, M. & SEATO, E. (1965). J. Appl. Phys. 36, 1453-1460. UYEDA, N., MURATA, Y., KOBAYASHI, T. & SEATO, E. (1974). J. C ys . G ow h, 26, 267-276. YANAGI, n., MAEDA, S., HAYASHI, S. & ASHIDA, M. (1988). J. C ys . G ow h, 92, 498-506. YANAGI, H., MAEDA, S., UEDA, Y. & ASHIDA, M. (1988a). Ul a- mic oscopy, 25,-1-12. YANAGI, H., MAEDA, S., UEDA, Y. & ASHIDA, M. (1988b). J. Elec on Mic osc. 37, 177-178. YANAGI, H., UEDA, Y. & ASHIDA, M. (1988). Bull. Chem. Soc. Jpn, 61, 2311-2320. Ac a C ys . (1989). C45, 1894-1897 S uc u e o 1-Me hyl-5-(D-galac o-l,2,3,4,5-pen aace oxypen yl)- 3-phenylpy azole BY C. F. CONDE AND A. CONDE Depa amen o de F[sica de la Ma e ia Condensada, Ins i u o de Ciencias de Ma e iales, Uni e sidad de Se illa-CSIC, Se illa, Spain (Recei ed 16 No embe 1988; accep ed 20 Ma ch 1989) Abs ac . C25H3oN2OI0, M = 518"5, o ho hombic, P21212 , a = 12.303 (2), b = 25.071 (4), c = 8-823 (5)/~, V= 2721.4 (16)/~3, Z = 4, Dx = 1"265 Mg m -a, a(Mo Ka) = 0.7107 A, /~ = 0.09 mm -~, F(000)= 1076, oom empe a u e, inal wR = 0.040 o 1424 obse ed e lexions. Bond dis- ances and angles a e all wi hin he expec ed anges. The py azole and phenyl planes a e wis ed by 18 °. To sion angles be ween he ace oxy g oups and he 0108-2701/89/121894-04503.00 pen yl chain ange om 45 o 80 °. The c ys al cohesion is mainly due o an de Waals in e ac ions bu he e a e wo possible hyd ogen bonds along [100] and [001]. Molecula -packing analysis in he a om-a om app oach yields an equilib ium con- igu a ion close o he expe imen al s uc u e. In oduc ion. The s uc u e de e mina ion o 1- me hyl- 5-(o-galac o- 1,2, 3,4, 5-pen aace oxypen yl)-3- © 1989 In e na ional Union o C ys allog aphy C. F. CONDE AND A. CONDE 1895 phenylpy azole was unde aken as pa o a con- inuing esea ch p ojec on C-nucleosides and hei p ecu so s. The biological p ope ies o py azomycin and o he py azole C-nucleosides ha e p opi ia ed he de elopmen o syn hesis me hods o hese and also o p ecu so s and analogous compounds. The i le compound (III) was p epa ed (G6mez-Guill~n & Lassale a, 1987, 1988) by eac ion o he suga ni oalkene (I) wi h a oma ic benzaldehyde me hyl- hyd azone (II). The p oposed s uc u e was assigned on he basis o chemical and spec oscopic p ope ies and he X- ay analysis was sugges ed in o de o elimina e he 2-py azoline o m (IV) and o es ablish he con o ma ional de ails o he molecule in he solid s a e. CH-NO~ CH H-C-OAc AcO-C-H AcO-C-H H-C-OAc CH2OAc (I) CH-C6H5 /C6H~ ,C6H S N I N NH R N ) R ~o [ l Me Me R=D-galac o-pen aace oxypen yl (II) (III) (IV) Expe imen al. Single c ys als in he o m o colou less p isms elonga ed along [001] p epa ed in he O ganic Chemis y Depa men o his Uni- e si y and kindly supplied by P o esso M. G6mez- Guill6n. C ys al 0.06 x 0.15 × 0.04 mm. Uni -cell pa ame e s om 25 e lexions 5 < 0 < 20 °. En a - Nonius CAD-4 di ac ome e , g aphi e mono- ch oma o , 2 < 20 < 60 ° (0 ___ h _< 17, 0 -< k <_ 35, 0 ___ l_< 12), w--20 scan mode. Two s anda d e lexions (310, 310); a ia ion in in ensi y less han 2% o he mean alue. 2728 independen e lexions measu ed, 1304 conside ed unobse ed [I < 2 (/)]. Lo en z and pola iza ion co ec ion, no co ec ion o abso p ion o ex inc ion. S uc u e sol ed by di ec me hods using MULTAN80 (Main, Fiske, Hull, Lessinge , Ge main, Decle cq & Wool son, 1980). Full-ma ix leas -squa es e inemen on F, aniso opic. Di e ence Fou ie syn hesis e ealed he H-a om posi ions; iso opic empe a u e ac o B = 4.0 A 2 o he H a oms. A inal con e gence A/ < 0.01, R = 0"059, wR = 0"040, S = 1"72 o 424 e ined pa am- e e s, w = 1/ Z(Fo). Numbe o e lexions/numbe o a iables = 3.4. Max. and min. alues in inal di e ence syn hesis 0-25 and - 0.20 e ,~,- 3, espec i ely. A omic sca e ing ac o s om In e - na ional Tables o X- ay C ys allog aphy (1974). C ys allog aphic p og ams o he XRA Y76 sys em (S ewa , Machin, Dickinson, Ammon, Heck & Flack, 1976) used h oughou . Table 1. A om coo dina es and equi alen iso opic he malpa ame e s ( x 10 3) Ueq = ~ Y.i Y~j U ija* a~' a,.ajcos( a i,aj). x y z u~(A 2) O41 1.0371 (7) 0.1756 (3) 0.5176 (10) 51 (4) 042 0.8934 (8) 0-2283 (4) 0-5752 (12) 85 (5) O51 1.1608 (7) 0-1282 (3) 0.2860 (10) 43 (4) 052 1-1579 (8) 0.1439 (4) 0.0367 (11) 71 (5) O61 0-9072 (7) 0.0651 (3) 0.3776 (10) 46 (4) 062 0.9092 (9) 0.0379 (5) 0.6181 (I I) 96 (6) O71 1.0532 (6) 0.0254 (3) 0.1313 (9) 43 (3) 072 1.2256 (6) 0.0057 (4) 0-0695 (1 I) 71 (4) O81 1.1150 (7) -0.0712 (3) 0.3057 (11) 55 (4) 082 1.0053 (8) -0.0952 (4) 0.1113 (13) 90 (5) NI 0.9395 (9) 0.2428 (5) 0.1856 (13) 47 (5) N2 0-9794 (9) 0-2881 (4) 0.1162 (12) 46 (4) C1 1-0155 (1 I) 0.2205 (5) 0.2789 (16) 37 (5) CII 0.8259 (9) 0-2273 (5) 0.1626 (17) 60 (6) C2 1.0832 (1 I) 0-2944 (6) 0.1650 (16) 44 (5) C21 1.1467 (12) 0-3350 (5) 0.0985 (19) 50 (6) C22 1-1171 (12) 0-3614 (6) -0.0277 (22) 77 (7) C23 1.1846 (16) 0.4043 (9) -0-0822 (32) 131 (12) C24 1.2811 (21) 0.4132 (9) -0.0242 (35) 130 (13) C25 1.3132 (16) 0.3876 (8) 0.1015 (23) 118 (11) C26 1.2442 (15) 0.3475 (6) 0.1640 (18) 90 (8) C3 1.1082 (9) 0.2523 (5) 0-2706 (14) 44 (5) C4 0-9899 (10) 0.1714 (5) 0.3666 (15) 42 (5) C41 0.9768 (13) 0-2090 (7) 0.6074 (17) 59 (7) C42 1-0337 (16) 0-2173 (9) 0.7621 (19) 130 (10) C5 1.0442 (9) 0.1225 (5) 0.2938 (14) 38 (5) C51 1.2114 (13) 0.1387 (6) 0.1476 (19) 67 (7) C52 1.3293 (11) 0.1437 (7) 0-1631 (18) 86 (8) C6 1.0256 (9) 0-0685 (5) 0-3722 (14) 39 (5) C61 0.8588 (13) 0-0497 (6) 0-5123 (20) 64 (7) C62 0.7381 (10) 0-0535 (5) 0-4931 (18) 67 (6) C7 1.0783 (10) 0-0220 (6) 0.2959 (13) 36 (5) C71 1.1382 (11) 0.0165 (6) 0.0325 (18) 59 (7) C72 1.0939 (11) 0.0186 (6) -0.1294 (15) 70 (7) C8 1.0409 (lO) -0.0313 (5) 0.3551 (15) 48 (5) C81 1.0882 (14) -0.1010 (6) 0.1807 (20) 65 (8) C82 1.1790 (13) -0.1378 (5) 0.1415 (18) 74 (7) Discussion. The inal a omic pa ame e s a e gi en in Table 1.* An ORTEP (Johnson, 1965) d awing o he molecule wi h a omic labelling is shown in Fig. 1. Bond leng hs and angles o non-H a oms a e lis ed in Table 2. The py azole ing is plana wi h he la ges displacemen o any non-H a om om i s plane being 0.008/~. The o ien a ion o he phenyl ing o he py azole plane can be de ined by he o sion angle C3--C2--C21--C22 = 161-0 (16) °. The i e ace oxy g oups a e plana and hei o sion angles wi h espec o he main pen yl chain a e C1---C4--O41--C41 = 76.3 (13), C4--C5-- O51--C51 -- - 106.0 (13), C5--C6--O61--C61 = - 133.7 (11), C6--C7--O71--C71 = 135.2 (11) and C7--C8--O81--C81---98.6(13) °. The Newman p ojec ions co esponding o C--C bonds o he main pen yl chain a e shown in Fig. 2 whe e he con igu a ion can be deduced. Molecula -packing analysis The c ys al cohesion is mainly due o an de Waals in e ac ions bu some in e molecula con ac s * Lis s o s uc u e ac o s, H-a om coo dina es and aniso opic he mal pa ame e s ha e been deposi ed wi h he B i ish Lib a y Documen Supply Cen e as Supplemen a y Publica ion No. SUP 52078 (14 pp.). Copies may be ob ained h ough The Execu i e Sec e a y, In e na ional Union o C ys allog aphy, 5 Abbey Squa e, Ches e CHI 2HU, England. 1896 C25H3oN2OIo Table 2. Bond dis ances (A) and angles (°) o non-H a oms O51-----C5 1.444 (14) O61--C6 1-460 (14) O41---C4 1.457 (16) O71---C7 1.487 (15) O81---C8 1"422 (15) O62--C61 1.159 (20) N1--Cl b366 (18) O82---C81 1-198 (20) N2---C2 1-357 (17) C6~C5 1-538 (18) C4~C1 1.487 (18) C42~C41 1.549 (23) C22--C23 1.440 (28) C2--C3 1.443 (19) C1~C3 1.394 (18) C26---C25 1.429 (26) C82--C81 1.489 (22) C25---C24 1.341 (35) C51---C52 1.462 (21) C5----4)51---C51 120-2 C4--O41---C41 111.0 C8---O81---C81 118.4 N2--N I--CI 1 119.8 N 1 --N2---C2 106-9 O61--C6----C7 113-7 O71---C7---C6 107.7 071----C7---C8 109.1 O41-----C4-----C 1 109-3 O81-----C8-----C7 108.7 N2--C2---C3 108.6 C21---C2---C3 132.8 C2---C~ 1--C26 118.3 N1--CI--C4 120.5 N I---C 1---C3 107.1 051 ---C5---C4 112-0 C2---C3--C 1 106- I C42---C41----O42 123-8 C21--C26--C'25 121.2 O62---C61---C62 129-7 O71----C71---O72 124.4 071---C71---C72 108-3 051---C51-----O52 119.6 O51--C51--C52 • 112-1 O81---C81---C82 110.1 C22--C23--C24 121.2 O51--C51 1.395 (19) O61---C61 1.385 (19) O41~C41 1"371 (18) O71--C71 1.380 (17) O81----C81 1.373 (19) NI--N2 1.379 (15) N]-----CI l 1.465 (15) O72----C71 1.156 (16) C6--C7 1.495 (18) C7---C8 1'507 (18) C4---C5 1.536 (18) C22--C21 1.345 (24) C2~C21 1.412 (20) C21~C26 1.367 (23) C41~D42 1.168 (19) C61---C62 1.497 (20) C71---C72 1.530 (20) O52-----C51 1'187 (19) C23--C24 1.312 (34) (10) C6---O61--C61 118'3 (10) (10) C7--O71--C71 116.7 (10) (l]) CI--NI---CI 1 128'8 (1]) (10) N2--N I~CI 111.2 (11) (10) O61--C6---C5 102.4 (9) (10) C7--C6---C5 114.8 (10) (9) C6--C7----C8 113.7 (10) (9) O41---C4---C5 105.5 (10) (10) C 1---C4---C5 110.5 (11) (10) C21--C22--C23 119.2 (16) (11) N2~C2--C21 118-3 (12) (12) C22--C21--C2 123.3 (14) (14) C22--C21---C26 118.4 (14) (12) C4--C1---C3 132-4 (12) (11) C6--C5--C4 116.7 (10) (9) 051---C5---C6 104.8 (9) (11) O41--C41--C42 110.3 (13) (15) O41---C41---4)42 125.9 (14) (16) O61----(261---O62 122.1 (14) (15) O61---C61--C62 108.1 (13) (14) O72---C7 I---C72 127.1 (13) (11) C26--C25----C24 118.7 (19) (14) O52--C51---C52 128.2 (15) (13) O82--C81--C82 126.5 (15) (13) O81--C81--O82 123.2 (14) (22) C25--C'24--C23 120.5 (13) espec o cell cons an s, molecula ansla ion and o a ion and also sub o a ion o he i e ace oxy g oups and he phenyl ing, s a ing om he expe i- men al s uc u e. Rep esen a i e esul s o he ene gy minimiza ion a e gi en in Table 3. As obse ed, he calcula ed equilib ium con igu a ion is in good ag eemen wi h he expe imen al s uc u e. The op imized s uc u e emains e y simila wi h ega d o he molecula pa ame e s as shown in Table 3. Shi s o he posi- ional and o ien a ional molecula pa ame e s a e 0.02 A and 2.6 °, espec i ely, and he a ia ions in he o sion angles o in amolecula elaxed o a ions a e lowe han 3 ° in all cases. The au ho s hank P o esso M. G6mez-Guill n o supplying he c ys als and P o esso A. L6pez- Cas o o collec ing he di ac ome e da a. This wo k is pa o a esea ch p ojec suppo ed by he CAICYT o he Spanish Go e nmen and he CSIC. ce2~ c"2~o,,2 ~L 7('~ C61~062 c,~ ~_~64~ .A - C2'J ~ (~051 071 (~ n o ,~'~A~ 082 ,~~ C22 4 TM C71.~ ~" ' "C81~ C23 ~i~, ~(~,~ c26 052 "~ C24" ':¢ 072 C82 Fig. l. An ORTEP plo o he molecule wi h a om labelling. may be conside ed as possible hyd ogen bonds. These in e ac ions a e C25--H25...O62(x+), -y+ ~, -z+l) linking molecules ela ed by a sc ew axis pa allel o [100] and C42--H423...O52(x, y, z+ 1) linking neighbou ing molecules along [001]. De ails o hese con ac s a e C25--H25 = 1.13 (5), C25...O62 = 3.32 (2), H25---O62 = 2.57 (3) A, C25--H25...O62 = 122 (5) ° and C42--H423 = 1.16 (6), C42...O52 = 3.40 (2), H423...O52 = 2.51 (3) A, C42--H423...O52 = 132 (5) °, bo h sa is ying he c i e ia o Taylo & Kenna d (1982) o hyd ogen bonds. The molecula geome y and c ys al packing we e compu ed by PARST (Na delli, 1983). La ice-ene gy calcula ions in he a om-a om po en ial app oach we e pe o med using he com- pu e p og am PCK6 (Williams, 1972). The in e ac- ion be ween a pai o non-bonded a oms is in he o m ~ = -A -6 + B exp(- C ) and he molecules a e assumed o be igid bodies bu in amolecula o a ions a ound selec ed bonds as axes we e elaxed. The se o po en ial pa ame e s is desc ibed else- whe e (Conde, Mill in, Conde & M~ quez, 1985). La ice-ene gy minimiza ion was pe o med wi h 051 59 041 62 -58 H5 -57 H4 C6 C4-C5 C5 H7 ~~.,. 071 H6 ~7o 7' 1-5' 061 C8 C6-C7 C4 C6 061 ~ H6 /~ H82 H5 071 - 57 -56 O51 75 ]-44~ H7 C7 081 C5-C6 C7-C8 Fig. 2. ° Newman p ojec ions co esponding o he C---C bonds h ough he main chain. To sion angles a e in °; e.s.d.'s a e in he ange 0.8-1.4 ° (excluding hose in ol ing H a oms). C. F. CONDE AND A. CONDE 1897 Table 3. Resul s o ene gy minimiza ion ~'c: molecula cen e o mass, 0: molecula o a ion. Cell cons an s Aa 0.4% Ab O.l Ac 0"5 Molecula pa ame e s IAT, i 0.02 A o 2.6 ° Sub o a ions (A ) C I --C4---O41---C41 I'1" C4-"425-"4) 51 -"'C 51 -2"3 C5--'C6---O61--'C61 - 1"8 C6""~7--O71 --C71 -0"6 C7---C8--O81--C81 -2"7 c3---c2--c2 I----c22 - 1.3 Re e ences CONDE, C. F., MILL~,N, M., CONDE, A. & MARQUEZ, R. (1985). ,4c a C ys . C41, 1658-1662. G6MEZ-GUILL ~N, M. & LASSALETTA, J. M. (1987). l l h In . Cong . He e ocycl. Chem. Heidelbe g, Fede al Republic o Ge many. G6MEZ-GUILLI~N, M. & LASSALETTA, J. M. (1988). 22nd Bienn. Reun. Span. R. Soc. Chem. Mu cia, Spain. In e na ional Tables o X- ay C ys allog aphy (1974). Vol. IV. Bi mingham: Kynoch P ess. (P esen dis ibu o Kluwe Academic Publishe s, Do d ech .) JOHNSON, C. K. (1965). ORTEP. Repo ORNL-3794. Oak Ridge Na ional Labo a o y, Tennessee, USA. MAIN, P., FISKE, S. J., HULL, S. E., LESSINGER, L., GERMAIN, G., DECLERCQ, J.-P. & WOOLFSON, M. M. (1980). MULT'4NSO. ,4 Sys em o Compu e P og ams o he Au oma ic Solu ion o C ys al S uc u es om X- ay Di ac ion Da a. Uni s. o Yo k, England, and Lou ain, Belgium. NARDELLI, M. (1983). Compu . Chem. 7, 95-98. STEWART, J. M., MACHIN, P. A., DICKINSON, C. W., AMMON, H. L., HECK, H. & FLACK, H. (1976). The XRA Y76 sys em. Tech. Rep. TR-446. Compu e Science Cen e , Uni . o Ma yland, college Pa k, Ma yland, USA. TAYLOR, R. & KENNARD, O. (1982). J. Am. Chem. Soc. 104, 5063-5070. WILLIAMS, D. E. (1972). Ac a C ys . A28, 629-635. Ac a C ys . (1989). C45, 1897-1899 S uc u e o 2-Me hyl-l,3-cyclopen anedione BY ANDRZEJ KATRUSIAK Depa men o O ganic Chemis y, Facul y o Chemis y, Adam Mickiewicz Uni e si y, G unwaldzka 6, 60-780 Pozna~, Poland (Recei ed 6 Oc obe 1988; accep ed 20 Ma ch 1989) Abs ac . C6H802, M = 112.13, monoclinic, C2/m, a = 12.766 (2), b = 6"807 (2), c = 6.4814 (8) A, /~ = 93.94 (1) °, V= 561.9 (2) .A, 3, Z= 4, Ox = 1.33 g cm-3, m.p. = 486-488 K, A(Mo Ka) = 0.71069 A, /x(Mo Ka) = 1.07 cm-~, F(000) = 240, T = 292 K, inal R = 0.040 o 541 obse ed e lec- ions. The s uc u e consis s o chains along z o hyd ogen-bonded enol molecules [O...O dis ance 2.598 (2) A]. The molecules lie on a mi o plane and he chains, in u n, a e a anged in laye s pe pen- dicula o y. The posi ions o he H a oms o he me hyl g oup a e well de ined and consis en wi h he cons ain s o he mi o plane, he H a om in he plane being on he side o he hyd oxyl g oup; a me as able posi ion o he me hyl H a oms, co e- sponding o a 180 ° o a ion o he me hyl g oup, has also been de ec ed. In oduc ion. This s udy o 2-me hyl-l,3-cyclo- pen anedione (MCPD) (enol o m) was unde aken p ima ily o es ablish he a angemen o he MCPD molecules in he c ys al and hei in e molecula in e ac ions. In he s uc u es o cyclic l-dike o- 0108-2701/89/121897-03503.00 me hanes in es iga ed so a he molecules a e in e - connec ed by s ong ---O---H...~ hyd ogen bonds sho e han 2.6 A, which o m chains - as has been obse ed in 1,3-cyclohexanedione (CHD) (E e , U ba iczyk-Lipkowska, Jahn & F ye, 1986), 1,3-cyclopen anedione (Ka usiak, 1989) and dimedone (5,5-dime hyl-l,3-cyclohexanedione) (Semmingsen, 1974; Singh & Cal o, 1975). I was demons a ed by E e , U ba iczyk-Lipkowska, Jahn & F ye (1986) ha , in he p esence o sui able gues molecules, cyclome s can be o med om he hyd ogen-bonded CHD molecules. We also wan ed o in es iga e he in e molecula hyd ogen bond and o compa e i wi h hose in simila s uc u es, and look a he molecula dimensions o he MCPD molecule, he wo old symme y o which is b oken by he al e na ing HO--C=C--C=O -bond sys em. Expe imen al. C ys als o MCPD we e ec ys allized om e hanol. Colou less, elonga ed pla es wi h y along he long and z along he sho edges o he pla es, dimensions 0-27 x 0.27 x 0.15 mm. The in en- © 1989 In e na ional Union o C ys allog aphy