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1978 185Crystal and Molecular Structures of {NN"[2-(2'-Pyridyl)ethyl]ethylene-bis(salicylideneiminato)}-iron(ii) and -cobalt(ir)-Ethanol (1 /I )By Geoffrey B. Jameson, Frank C. March, Ward T. Robinson,. and Seah Sen Koon, Department ofThe crystal and molecular structures of the title complexes, [Fe(salpeen)] (1 ) and [Co(salpeen)]*EtOH (2). havebeen determined using three-dimensional X-ray diffraction data collected on automatic diffractometers. Complex(1) crystallises in the monoclinic space group P2,lcwith the unit-cell parameters a = 10.572(2), b = 11.465(2), c =16.640(3) A, p = 90.52(1 ) O , and Z = 4, and its structure has been refined by conventional least-squares techniquesusing 1 11 8 reflections having / > 30, to give R 0.056 and R' 0.062. Complex (2) crystallises in the triclinic spacegroup P i with the unit-cell parameters a = 15.049(2), b = 15.127(2), c = 10.258(1) 8, a = 90.53(1), p =93.53(1), y = 109.81 (l)', and Z = 4, and its structure has been refined using 1 237 reflections having / > 3ct1 togive R 0.064 and R' 0.069.The cobalt complex thus has two crystallographically independent molecules in theasymmetric unit, each hydrogen bonded via an oxygen atom to an ethanol adduct molecule; there are small butsignificant differences between the two molecules. The iron and cobalt complexes have a similar distortedt r i go na I - b i pyra m id a I geometry .Chemistry, University of Canterbury, Christchurch, New ZealandTHE structures of five-co-ordinate complexes of iron(I1)and cobalt(I1) are of some significance with regard tochanges in geometry that occur on formation of adioxygen adduct.Studies of such complexes, containinga dianionic quadridentate ligand capable of assuming anessentially square-planar geometry (such as a porphyrinor Schiff base) or a conjugated amine ligand (such asimidazole or pyridine) , are comparatively rare. In theircrystal structures, the tetraphenylporphinato-complexes[Fe(tpp)(2Me-im)],l [Co(tpp)(lMe-im)],2 [Co(tpp)(l,2Me2-im)],3 and [Co(tpp) (3,5Me2-py)] 495 are all square pyrami-dal.? The complex [Co(salen) ( p ~ ) ] , ~ which features themore flexible Schiff-base ligand, also exhibits square-pyramidal geometry in the crystalline state, but [Co-(3F-saltmen) (1Me-im)] has a distorted trigonal-bipy-ramidal geometry.' The complex [Co(salbn) (py)] cry-stallises with two crystallographically independentmolecules ; one has square-pyramidal geometry, theother distorted trigonal-bipyramidal geometry.8In this paper the crystal and molecular structures ofthe title complexes [Fejsalpeen)] (1) and [Co(salpeen)] (2)are reported and compared.The cobalt complex andits dioxygen adduct have been communicated b r i e f l ~ . ~The following paper lo gives the full crystal and molecularstructure of the dioxygen adduct and discusses stereo-chemical changes accompanying oxygenation. Theiron(r1) complex does not form an easily isolable dioxygenadduct; rapid irreversible oxidation of the type com-monly observed for iron(I1) complexes l1 is presumed tohave occurred.f Abbreviations : tpp = meso-Tetraphenylporphinate ; salen =NN'-ethylenebis (salicylideneiminate) ; 3F-saltmen = NN'-tetramethylethylenebis( 3-fluorosalicylideneiminate) ; salpeen- NN'- [ 2- (2'-pyridy1)ethyllethylenebis (salicylideneiminate) ;1Me-im = l-methylimidazole ; 2Me-im = 2-methylimidazole ;1,2Me2-im = 1,2-dimethylimidazole ; 3,5Me,-py = 3,bdimethyl-pyridine ; py = pyridine ; salbn = NN'-butane-l,4-diylbis(sali-cylideneiminate) .Throughout this paper: 1 B.M.3 9.27 x lovz4 Am2.D. A. Buckingham, J. P. Collman, J. L. Hoard, G. Lang, J. L.Radonovich, C. A. Reed, and W. T. Robinson, unpublished work.W. R. Scheidt, J . Amer. Chem. SOC., 1974, 96, 90.3 R. N. Dwyer, P. Madura, and W. R. Scheidt, J . Amer. Chem.SOC., 1974, 96, 4815.W. R.Scheidt and J. Ramanuja, unpublished results quotedin ref. 5.5 J. L, Hoard, in ' Porphyrins and Metalloporphyrins,' ed.K. M. Smth, Elsevier, Amsterdam, 1975, ch. 8.EXPERIMENTALThin plate-like red crystals of LFe(salpeen)] (1) and[Co(salpeen)] (2) were both prepared according to ref. 9(a).Both complexes are high spin: p e ~ . = 5.14 for (1) and4.25 B.M. for (2) a t 20 "C.1 Crystal data and data-collec-tion procedures are summarised in Table 1. The intensitydata obtained were corrected for background and Lorentzand polarisation effects. The intensities of three standardreflections well separated in reciprocal space were used toensure that the relative intensity data for each analysiswere correctly scaled.Throughout this work full-matrix least-squares refine-ments were based on F, and the function minimised wasA == Xw(lFol - lFcl)z.The weights, w, were taken as41/a12 where aI is the standard deviation in the intensityI estimated from counting statistics. lFol and IF,I are theobserved and calculated structure-factor amplitudes,respectively. Agreement factors were defined as R =The standard error in an observation of unit weight was[A/(No - Nv)]' where No is the number of observations andNv the number of variable parameters used to describe thestructural model. Atomic-scattering factors for non-hydrogen atoms were taken from Cromer and Mann,12for hydrogen atoms from Stewart et aZ.13 The effects ofanomalous dispersion for iron and cobalt were included inF, (ref.14) using Cromer's values.lS[Fe(salpeen)] (1) .-The structure was solved by directmethods. Phases were obtained for 428 out of the 464strongest E values. Notwithstanding a program bug whichresulted in the E map being calculated with all the E valueshaving the same magnitude, elucidation of most of thecqp01 - I&ll)/qF,I and R' = [ W I F c I - I ~ ~ l ) " ~ ~ I ~ O l " ] ' .M. Calligaris, D. Minichelli, G. Nardin, and L. Randaccio,J . Chem. SOC. ( A ) , 1970, 2411.A. Avdeef and W. P. Schaefer, personal communication.N. Bresciani, M. Calligaris, G. Nardin, and L. Randaccio, J .Chem. SOC. ( A ) , 1970, 498.@ (a) J. P. Collman, H. Takaya, B. Winkler, L. Libit, S. S.Koon, G. A. Rodley, and W. T. Robinson, J . Amer.Chem. SOC.,1973, 95, 1656; (b) W. T. Robinson, Abs. A.C.A. Winter Meeting,Gainsville, 1973, p. 15.lo G. B. Jameson, G. A. Rodley, and W. T. Robinson, followingpaper.l1 A. B. Hoffman, D. M. Collins, V. W. Day, E. B. Fleischer,T. S. Srivastava, and J. L. Hoard, J . Amer. Chem. SOC., 1972, 94,3620.l2 D. T. Cromer and J. B. Mann, Acta Cryst., 1968, A24, 34.l3 R. F. Stewart, F. R. Davidson, and W. T. Simpson, J . Chem.l4 J. A. Ibers and W. C. Hamilton, Acta Cryst., 1964, 17, 781.l5 D. T. Cromer, Acta Cryst., 1965, 18, 17.Phys., 1965, 42, 3176J.C.S. Daltonstructure was possible. Remaining non-hydrogen atompositions were established using Fourier syntheses, and theirpositional and thermal parameters refined. Most hydrogenatoms were located in Fourier syntheses and included in themodel a t their idealised positions with r(C-H) 1.0 A andtemperature factors derived from those of the attachedcarbon atom, uiz.BH = Bc + 1.0 Hi2. The hydrogenatoms were not refined and their positions were recalculatedafter each cycle. Refinement converged satisfactorily(Table 1). The final error in an observation of unit weightwas independent of F, and (sinO)/h indicating a satisfactoryweighting scheme. There was no evidence for secondarystructures. Here and elsewhere the estimated standarddeviation in the least significant digits is quoted in paren-theses and is conventionally derived from the inverse of theleast-squares matrix.Calculations were carried out a t the University of Canter-bury, New Zealand using a Burroughs 6718 computer;the data-processing program HILGOUT is based on pro-grams DRED (J.F. Blount) and PICKOUT (R. J . Doedens).Numerical absorption corrections were applied using DABS,a modified version of DATAPH (P. Coppens). Structure-factor calculations and least-squares refinements werecarried out using program CUCLS and Fourier summationsTABLE 1Crystal data and data collection[Fe(salpeen)] (1) [Co(salpeen)] (2)Molecular formula C23Hz1FeN3Oa C2,H2,CoN30,C,H,0Formula weight 427.3 476.5Crystal symmetry monoclinic triclinicSpace group ' P2,/c (no. 14) Pi bz 4 4Crystal dimensions(mm) 0.18 (max.), 0.06 (min.) 0.33, 0.25, 0.03p/cm-lTransmission coefficientsDiffractometer Syntex P2, (four-circle) Hilger and Watts (four-circle)Temperature (0J"C) 20 23Monochromatisat ion Graphite monochromator Zr filterScan type 8-20 symmetric 8-28 symmetricb J (A) 10.572(2), 11.465(2), 16.640(3) 15.049(2), 15.127(2), 10.258(1)@ J Y (") 90, 90.52(1), 90 90.53( 1) , 93.53( 1) , 105.81 (1)Dm(g :m-3) 1.41, 1.40(1) (flotation) 1.41, 1.30(1) (flotation) d8.31 (Mo-Ka, A 0.710 7 8)0.98 (max.), 0.79 (min.) (I63.1 (Cu-Ka,, A 1.541 8 8)0.70 (max.), 0.55 (min.)0.72721818.0, 0.43Scan width (") fScan time (t/s) fBackground time ( t / s ) femax./", (sin e ) / A (A-1)Number of unique intensitiesNumber of intensities withp Factor for optimal weighting 0.05 h50.0, 0.50collected 2 401 3 105I > 3ar 1118g 1237g0.06129 x 2 Number of variable parameters 122Final shift /e.s.d .0.02 0.10Final R, R' 0.056, 0.062 0.064, 0.069Error in observation of unitweight 1.52 1.35a ' International Tables for X-Ray Crystallography,' Kynoch Press, Birmingham, 1962, vol. 1.Cell parameters, crystal orientation, and data collection a t 20 "C for (1) and a t 23 "C for (2).By structure determination.Loss of adduct occurred. DataJVariable: based on aP. W. R. Corfield, R. J. Doedens, andfor (2) but not (1) were corrected for absorption using DABS, a local version of DATAPH (P. Coppens).preliminary scan through each reflection.J. A. Ibers, Inorg. Chem., 1967, 8, 197.Only data having I > 3 q used in refinement.extinction among strong low-angle reflections. For datahaving I < 3 q there weie no serious or systematic dis-crepancies between F, and F, with respect to 01.[Co(salpeen)].EtOH (2) .-Space group PI, with twocrystallographically independent molecules in the formulaunit, was assumed and subsequent refinement confirmedthis choice.A three-dimensional Patterson synthesisyielded co-ordinates for the two cobalt atoms of the asym-metric unit. Successive cycles of least-squares refinementsand Fourier syntheses established co-ordinates for the non-hydrogen atoms and for some hydrogen atoms. All thehydrogen atoms in [Co(salpeen)] were included in the modelas before. Refinements were conducted in two blocks witheach block containing the two cobalt atoms, the twoethanol adduct molecules, and one or other of the twocrystallographically independent salpeen ligand systems.Refinements converged satisfactorily (Table 1).Theweighting scheme was satisfactory and there was no evidencefor secondary extinction.Table 2 lists the final atomic parameters for both crystalusing FOURIER. These are highly modified versions ofORFLS (W. R. Busing, K. 0. Martin, and H. A. Levy), andFORDAP (A. Zalkin), respectively. Programs SHNORMand SAP, derived from NRC-4 (S. R. Hall and F. R. Ahmed),were used to calculate normalised structure factors (Evalues) and derive phases.Comprehensive tables of structure factors, bonddistances, bond angles, non-hydrogen intermolecular con-tacts (<3.75 A), and selected least-squares planes and thedeviations of atoms therefrom are deposited as Supple-mentary Publication No.SUP 22173 (22 pp.).* A selectionof torsional angles is deposited in the supplementarymaterial of the following paper.DISCUSSIONThe crystal structure of (1) consists of well separatedmolecules of {NN'-[2-(2'-pyridyl)ethyl]ethylenebis(sali-* For details see Notices to Authors No.7, J.C.S. Dalton, 1977,Index issue1978 187TABLE 2Final atomic parameters[Fe(salpeen)] [Co(salpeen)] (A) “Wsa1peen)l (B) - L L c - X(a) Refined atoms a077 33(14)-016 8(6)226 9(5)-097 2(7)132 O(7)161 l ( 7 )038 8(9)052 4(10)033 9(9)145 7(9)229 9(10)323 4(11)337 2(11)252 5(11)-090 3(10)-209 9(9)-232 6(8)-362 2(9) - 392 7(10) - 302 O(10)-174 0(9)-137 7(9)335 9(9)237 8(10)447 8(10)542 l(10)528 2(10)420 4(9)324 0(9)(b) Hydrogen atomsH(1A) -157H(1BI -104Hl2l ’ 054H(3A) - o i i140-038H(4B) 012H(6) 222~ j i a j -484H(14) -328H(15) -109H(20)253 457 H(22) 621H(23) 596HP4) 412H(25)H(S1A)H(S1B)Y242 12(14)341 9(5)334 2(5)177 O(7)125 8(7)126 O(7)033 7(9)007 9(9)090 9(10)-065 9(10)-042 6(9)-060 2(9)-011 4(11)172 7(10)207 6(8)292 6(8)310 2(9)383 3(10)430 8(8)352 2(8)124 4(9)209 6(8)192 9(9)273 3(10)376 O(10)396 7(9)312 9(9)109 l(11)443 5(9)030133-000-127-098-118-147-06201 314826017026939349847505811925843 6473z656 21(8)581 2(3)685 6(3)692 6(4)747 7(4)570 6(4)760 6(6)761 7(6)700 7(6)611 9(6)568 7(6)526 4(6)482 6(7)482 3(7)527 7(6)669 l(6)606 8(5)585 3(6)523 5(6)482 8c6)501 2(6)565 5(5)786 5(6)780 9(6)827 O(6)828 9(6)787 S(6)740 6(6)733 9(6)753813816716708606585528451451528696615508439471824869860791711Bb4.0(1)4.0(1)3.85(17)4.19( 18)4.19(18)4.7(2)5.2(3)4.5(2)5.2(3)6.6(3)7.0(3)6.1(3)4.2(2)4:6[2)5.6(3)5.3(2)4.3(2)3.6(2)4.5(2)3.8(2)5.1(3)5.2(2)4.6(2)4.0(2)5.5(3)5.7(3)3 5 2)5.4(3)d.. “ x Y z B X Y 2 B ’180 9(2)141 5(9)253 4(9)071 3(11)206 2(12)293 l(11)067 6(14)160 2(15)213 l(15)227 2(17)304 5(16)390 7(20)455 9(16)444 9(15)360 4(16)001 5(14)-002 6(16)-079 7(16)-091 O(16)-022 9(17)052 6(15)066 7(15)263 4(14)319 4(13)381 3(14)433 6(15)423 2(15)364 O(15)307 2(14)273 7(11)308 7(18)231 8(19)024042152183279166231390514497352057-129 - 147-033103271388482456364353347093 4(2)087 l(8)010 3(8)127 5(10)091 7(11)215 7(10)135 O(14)147 6(15)252 9(15)306 2(16)297 8(15)367 5(18)356 2(15)279 9(16)211 7(14)133 5(12)126 O(14)143 3(14)138 7(15)117 l(15)100 6(14)105 057 6(14)006 4(13)-029 4(13)-081 2(15)-100 O(l4)-069 7(14)-017 3(18)082 7(11)002 S(18)-083 6(18)-007 2(3)169 l(12)036 6(12)021 7(15)-073 8(15)-189 l ( l 6 )-218 7(20)-272 5(20)-267 3(21)-140 5(24)-049 5(20)-036 5(25)-057 3(23)-131 9(20)108 9(20)-012 4(19)126 9(22)-181 9(22)312 l(23)389 8(21)347 5(21)210 8(21)-243 3(19)-173 l ( l 9 )-240 8(19)-186 5(22)-056 7(23)-039 l(20)018 l(20)374 3(15)365 5(23)354 8(24)076 -258187 - 246127 - 370286 -335259 -294281 -095373 -158367 -035a12275151140163150111086065-014 - 102-146-083003011~~~072199167-068121352488415--.345-336-237-0181174402823.93 (9)3.9(3)3.7(3)3.2(4)3.9(4)3.0(4)3.9(5)4.3(6)4.7(6)6.0(7)4.2(5)5.0(6)4.5(6)4.0(5)2.7(5)4.4(6)4.7(6)4.9(6)4.8(6)3.6(5)3.2(5)2.7(5)3.2(5)4.4(6)4.7(6)4.1(6)3.5(5)7.6(5)6.2(7)7.0(7)7.3(7)3.9(5)c187 6(2)146 2(10)258 3(9)070 2(12)213 4(12)296 2(11)065 4(15)159 3(15)210 3(15)222 3(14)304 O(15)379 7(16)449 5(16)443 l(16)365 5(16)001 5(15)-001 9(16)-081 8(16)-093 8(16)-023 5(18)056 9(15)070 4(15)268 O(14)324 4(14)389 3(17)444 9(15)437 3(16)375 8(15)316 6(14)280 l(10)297 9(16)216 2(19)038026154275177224159387509494363-058-137 - 147-036109275398489479375336335-499 3(2)-517 7(9)-375 l(8)-588 6(11)-485 6(12)-566 l(11)-597 7(14) - 565 6(15)-643 8(15)-690 4(14)-640 O(14)-674 2(14)-630 2(16)-557 l(16)-625 2(14)-628 3(14)-627 2(15)-681 O(15)-687 8(15)-632 9(16)-576 7(14)-572 l(14)-421 O(l4)-338 l(14)-277 8(17)-196 4(16)-178 2(15)-236 6(15)-320 9(14)-438 7(11)-344 8(17)-306 5(18)-665-561 - 548-617-693-755 - 698 - 731-650 - 524 - 465 - 664-715-733-630-538-427-296-150-119-219 - 320 - 312494 4( 3)669 9(12)530 l(12)422 l ( l 6 )306 4(15)518 7(16)277 7(21)225 O(20)233 3(21)360 9(20)451.3(19)471 5(19)559 5(23627 9(21{606 2(20)483 3(21)623 673 O(22)7(808 6(23)888 9(22)846 9(21)711 l(20)249 l(19)321 l(21)250 2(21)305 8(22)437 8(23)510 7(19)458 6(20)872 8(14)865 2(22)851 8(25)2452331282051643374034215757006614266078459859161491552474816097889473.68(9)4.2(3)3.5(3)4.1(4)3.9(4)3.9(4)4.2(5)4.1(5)5.0(6)3.6(5)3.2(5)4.7(6)4.9(6)3.8(5)4.0(5)4.2(6)4.7(6)4.7(6)5.3(6)4.3(6)2.9(5)5.0(6)4.7(6)5.3(6)3.6(5)3.2(5)6.6(4)5.8(6)7.8(8)3.7(5)3.4(5)3.4(5)a Fractional co-ordinates are generated by placing 0.prior to the first digit. b Anisotropic parameters for Fe: Bll = 0.009 33(16), Is,, = 0.005 88(13), 838 = 0.003 43(6), Is1, = 0.000 09(17) Bls = -0.000 27(7), BS3 .= 0.000 45(10), where the form of the anisotropic thermal ellipsoid is exp[Bllh1 + &,k* 4- Baala + 2@&k j- 2Bl& + 2Ba3kl].Root-mean-square’components of thermal displacement along the principal ellipsoidal axes are 0.193(3), 0.220(2), and 0.233(2) A. c Hydrogen-atom positions were not re-fined. e All the hydrogen atomswere given a temperature factor of BH = 6.0.Hydrogen atom H(1A) is bonded to carbon atom C(1), etc. d Temperature factor derived from attached carbon atom, BH = Bc + 1.cylideneiminato)}iron(II) .Figure 1 provides a per-spective view of complex (1) together with the atom-labelling scheme. The only non-hydrogen intermole-cular contacts less than 3.5 are: O(2) C(l) 3.40,0(1) C(2) 3.43, C(6) 9 C(11) 3.47, and N(l)C(3) 3.47 A. The Fe C(3) intermolecular separationis rather close at 3.53 A. Figure 2 is a stereoscopic viewof the contents of the unit cell.The cobalt crystal structure comprises two crystallo-graphically independent molecules of (2) with eachmolecule hydrogen bonded to an ethanol molecule[O(Sl)-H 0(1) 2.82 A for both molecules A and B].Figure 3 is a stereoscopic view of the packing of (2) andthe ethanol adduct molecule in the unit cell. Closestcontacts not involving hydrogen atoms are: C(15)O(S1) 3.39, C(13) C(20) 3.40, C(24) C(24) 3.41,C(15) O(S1’) 3.43, C(8) C(8’) 3.44,0(2) C(S1)3.44, and O(2’) C(S1’) 3.46 A.* The relative* Here and elsewhere, atoms of molecule B are distinguishedfrom those of A by a single prime.orientations of the ethanol adduct molecule to the com-plex are strikingly similar for the two crystallographic-ally independent species, The co-ordination of a pyridylgroup (which is linked by an ethyl group to the ethyleneFIGURE.1 Perspective diagram of [Fe(salpeen)], showing theatom-labelling scheme, drawn using ORTEP2 (C. K. Johnson).The ellipsoids enclose 30% probabilit188 J.C.S. Daltonbridge of the Schiff base) induces deviations of the quad-r ident at e bis (salic ylideneiminat e) fragment from thesquare-planar conformation commonly adopted in theethylenebis(benzoy1acetoneiminate) and 3But-saltmen =NN'- tet r amethylethylenebis (3- t -but ylsalic ylidene-iminate)].FIGURE 2 Stereoscopic view down the a axis of the packing of [Fe(salpeen)] in the unit cell.Perspective view distance, 30 inFIGURE 3 Stereoscopic view down the c-axis of the packing of [Co(salpeen)] in the unit cell. Perspective view distance, 30 i nfour-co-ordinate species such as [Co(salen)] ,16 [Co- In both crystal structures the geometry is distorted(bzacen)],17 and [Co(3But-saltmen)] l8 [bzacen = NN'- trigonal bipyramidal with the O( 1)-Fe-N(2) group as the18 W. P. Schaefer and R. W. Marsh, Acts ~ v y s t . , 1969, B25, quasi-three-fold axis.The bond angle O(1)-Fe-N(2) isl7 G. A. Rodley and W. T. Robinson, unpublished structure l8 R. S. Gall, J. F. Rogers, W. P. Schaefer, and G. G. Cristoph,J . Amer. Chem. Soc., 1976,98, 5135.1675.determination1978165.4(3)" [173.5(6) and 172.8(7)"].* In the co-ordination N, moiety is non-planar. The dihedral angle betweenpolyhedra, the most notable differences between (1) and planes O(1)-Fe-N(l) and 0(2)-Fe-N(2) is 30.7" (25.2 and(2) involve the M-N(sa1en) separations and the O(1)- 30.6") and the torsional angle N(1)-0(1)-0(2)-N(2) isM-O(2) bond angles. The Fe-N(sa1en) separations are 16.3(3)' [12.6(5) and 17.2(5)"]. Table 4 lists dihedral0.08 A greater than the Co-N(sa1en) separations, and angles between a selection of least-squares planes andthe 0(1)-Fe-0(2) angle is more than 10" greater for (1) also the mean absolute displacement of atoms from athan for (2).This is compensated for by contractions, particular plane. The two chelate rings, chelate 1TABLE 3Selected bond distances (A) and angles ("); the values for the molecules A and B of (2) follow those of (1)1.958( 6)1.933( 13)1.939( 13)1.960( 6)1.926 ( 10)2.08 5 ( 7)1.945( 14)2.004( 16)2.10 1 (8)1.929( 17)1.992 ( 16)2.147(8)2 142(13)2.147(14)1.5 14( 12)1.50(3)1.50( 3)1.536 ( 13)1.57(3)1.58 (2)1.5 13( 13)1.50(3)1.52( 3)1.504( 12)1.48 (3)1.51(3)1.909( 10)O( 1)-M-N( 1)0 (2)-M-N( 2)N ( 1)-M-N (2)0 ( 1)-M-N (2)N ( 1 )-M-0 ( 2)N (1)-C( 1)-C( 2)N (2)-C( 2) -C ( 1)N( 2) -C( 2) -C( 3)c ( 1)-c (2)-C( 3)87.0 (3)9 1.8( 6)90.5(6)86.8 (3)92.5(6)90.2( 6)7 8 4 3)83.8( 7)82.9 (7)104.4( 3)89.6(5)94.0( 5)146.6 (3)155.5 (6)149.2( 6)109.3 (8)1 1 2.5 ( 18)11 1.8( 18)107.1(8)104.7(17)10 7.6 ( 1 7)11 1.4(8)1 13.4( 17)109.1(17)113.8(8)109.1( 18)1 1 0.6 ( 1 8)N (2)-M-O ( 1) 165.4( 3)173.5( 6)172.8( 7)N (1)-M-N( 3) 110.0(3)108.6(6)110.3(6)N(2)-M-N(3) 88.6 (3)88.9 (6)88.3( 6)0 ( 1)-M-N (3) 98.6(3)97.0 (5)96.8(6)95.5(6)99.4 ( 6)119.8( 18)12 1.3 (1 8)1 1 6.8 ( 20)115.4( 17)0 (2)-M-N (3) 99.4(3)C(2)-C(3)-C(4) 120.1(9)C(3)-C(4)-C(5) 116.1(9)nFIGURE 4 Perspective diagrams of [Fe(salpeen)] (a) and molecules A(b) and B(c) of [Co(salpeen)].The orientation-defining vectorsin each case are formed from the same atom combinationswhich are distributed fairly evenly, among the otherbond angles involving the metal and the salen liganddonor atoms.Table 3 t lists selected bond distancesand angles for the co-ordination polyhedra of (1) andthe two independent molecules of (2). Differences inM-O(sa1en) separations for (1) and (2) are small and thethree M-N (py) separations are essentially identical.Figure 4 illustrates qualitatively small differencesamong the three molecules (l), (2A), and (2B). Foreach case the orientation-defining vectors are formedfrom the same atom combinations. Quantitatively, thefollowing conformational aspects are noted. The Fe0,-* Immediately following a parameter for (l), the correspond-ing parameters for molecules A and B of (2), respectively, arequoted in parentheses.and 2, are not coplanar; neither are the two salicylidene-iminate residues sal 1 and 2.The atoms comprisingthese planes are listed in Table 4.[ 6 = (ClXPIlX,~,. - XMXt,,,,I)/-ClXMX,h,,,l] indicates that (1) exhibits greater depart-ures from ideal trigonal-bipyramidal or square-pyramidalsymmetries than (2).The Zemann testt Bonded distances and angles together with the estimatedstandard deviations (e.s.d.s) were calculated using CORFFE (alocal version of ORFFE; W. R. Busing, K. 0. Martin, and H. A.Levy). Torsional angles were calculated using GEOM and un-weighted least-squares planes, the dihedral angles between them,and displacements of atoms therefrom using MEAN PLANE (M.E.Pippy and F.R. Ahmed). Diagrams were obtained usingORTEP2, a local version of ORTEP-I1 (C. K. Johnson, 1970).l9 J. Zemann, 2. anorg. Chem. 1963, 324, 241190 J.C.S. DaltonThe co-ordinated pyridyl group has a number ofinteresting features as a consequence of its attachment tothe salen component. First, it is slightly rotated aboutits normal so that the Fe-N(3)-C(5) angle is 125.5(7)'[126.1(9) and 127.1(9)"] and it is tilted with respect tothe Fe-N(3) vector so that the iron atom is 0.516(1) A[0.293(3) and 0.120(3) A] out of the pyridyl plane. Thisalleviates close ethylpyridyl contacts with the salengroup. Secondly, the pyridyl plane is orientated withrespect to the salen component such that the torsionalbond length (0.011--0.013 A). For (2) the higher e.s.d.sassociated with individual bond lengths mask anypossible significance in such dispersion.In addition,differences between chemically equivalent bonds in thetwo phenyl groups for each molecule are statisticallyinsignificant. The internal consistency is reassuring,but, more importantly, the average bond length foreach class closely parallels the well characterised patternof three long inner bonds and three short outer bondsobserved for other related salen derivatives.20 NoTABLE 4Angles (") between normals to the planes *Id / A = 0.213, 0.157, 0.216Ph 1C(11), C(12), C(13), C(14), C(15), C(l6)d / A = 0.005, 0.007 0.015N(1), 0(1), N(2), O(2)sal 1N(1), C(lO), C(11) - * .C(16), 0(1)dlA = 0.029, 0.023, 0.024sal 2N(2), C(20), C(21) * d / A = 0.047, 0.011, 0.020Chelate 1* C(26), O(2)M, N(I), C(10), C(11), C(16), O(1)d/A = 0.015, 0.023, 0.026Chelate 2M, "2), C(20), C(21), C(26), O(2)J18 = 0.050, 0.049, 0.057Chelate ChelateP h 1 Ph 2 py sal 1 sal 2 1 216.5 14.0 70.1 16.1 11.8 16.3 11.513.5 7.5 75.9 13.2 7.0 13.7 8.315.8 7.3 80.5 15.7 7.7 15.8 9.930.1 64.6 1.6 28.0 3.2 28.020.5 69.3 0.8 20.0 1.9 21.722.0 73.2 0.3 22.5 0.9 25.72.4 29.2 5.8 71.3 29.376.6 20.1 0.5 20.3 2.879.4 21.8 0.5 21.7 5.463.3 71.8 61.7 75.668.7 76.6 67.5 79.473.2 79.7 72.5 84527.3 1.7 27.619.6 1.2 21.422.3 0.7 25.527.3 4.119.9 2.822.2 5.027.821.825.6* = Mean absolute displacement of atoms (8) from their least-squares plane in the order (I), (2A), and (2B).The order of thedihedral angles in descending the columns is (1), (2A), and (2B).angle N(l)-Fe-N(3)-C(5) is 31.4(8)" [29(2) and 27(2)"] andN(2)-Fe-N(3)-C(5) is 45.9(8)' [54(1) and 55(2)"]. Anon-eclipsing conformation avoids close salen-py con-tacts. Thirdly, there is evidence of stress in the ethylgroup which links the py and salen components. AtomC(4) is displaced by 0.13(1) A [0.11(2) and 0.11(3) A]from the pyridyl plane, and there are highly significantdepartures of the C(2)-C(3)-C(4) and C(3)-C(4)-C(5) bondangles from ideal tetrahedral symmetry (Table 2).Moreover, in all the three molecules the C(2)-C(3) bondsare longer than the other C-C bonds involving sp3-hybridised carbon atoms, although the differences are ofmarginal significance. The ethylene bridge adopts themore usual gauche conformation 2o with the torsionalangle N(l)-C(l)-C(2)-N(2) being 43(1)' [36(2) andFor (1) the dispersion (e.s.d.0.029 A) of the 12 phenylC-C bonds about their mean [1.397(29) A] is statisticallysignificant in comparison with the e.s.d. of an individual37 (2) "1.significant deviation of the phenyl C-C-C bond anglesfrom their mean value of 120.0' occurs for the threemolecules. The phenyl rings (and also the pyridyl ring)are approximately planar ; they are also coplanar withtheir associated chelate rings. Departures of atomsfrom the least-squares planes for the two nine-atomsalicylideneiminate residues are modest.The two crystallographically independent molecules of(2) provide an excellent demonstration of the effects ofcrystal packing on molecular stereochemistry. In theimmediate co-ordination sphere the most notabledifference between the two molecules of (2) is in theCo-N(sa1en) separations : for #molecule A the averageseparation is 1.94 k, for molecule B, 2.00 A.The differ-ences are statistically significant. Other small differ-ences between the two molecules are best appreciatedqualitatively by inspection of Figure 4. Small differ-2o M. Calligaris, G. Nardin, and L. Randaccio, Co-ordinationChem. Rev., 1972, 7, 3851978 191ences in (i) the dihedral angles between the planesO(l),Co,N(l) and 0(2),Co,N(2), (ii) the torsional anglesN(l)-O(l)-0(2)-N(2), and (iii) the disposition of thecobalt atoms with respect to the pyridyl plane are noted(see above).Even more pronounced differences between twocrystallographically independent molecules are observedfor [Co(salbn) (py)] ; one molecule has square-pyramidalgeometry, the other is a distorted square pyramid.8Thus, in comparing related structures, small differencesin stereochemistry about the metal centre may bemanifestations of crystal packing and not of intrinsicelectronic demands of the metal centre.The considerable rearrangement of the quinquedentatesalpeen ligand that accompanies the co-ordination ofdioxygen to [Co(salpeen)] is described in the followingpaper.We thank the Medical Research Council of New Zealandfor partial support, the assistance of the New ZealandUniversities Grants Committee for equipment and for aShirtcliff e Fellowship and Postgraduate Scholarship (toG. B. J.), and Professor J, P. Collman for crystals of thecobalt complex 9a and for use (by W. T. R.) of preparativefacilities a t Stanford University, California.[6/2123 Received, 17th November, 1976

ISSN:1477-9226    

DOI:10.1039/DT9780000185

出版商:RSC    

年代:1978

数据来源: RSC