Complexes of Ligands derived from I ,8=Dihydroxy-naphthalene. Synthesis and Crystal Structures of aPalladium and a Copper Complex"Bernard F. Hoskins, Christine J. McKenzie and Richard RobsonSchool of Chemistry, University of Melbourne, Parkville 3052, Victoria, AustraliaA simplified synthesis has been elaborated for 2,7-diacetyl-l,8-dihydroxy-3,6-dimethylnaphthalene,H,daddn, whose di-Schiff base derivatives in principle offer binuclear metal complexes withpotentially useful geometrical features; only mono-Schiff base products, however, are formed uponcondensation with the mono-primary amines 2-aminomethylpyridine, 2-aminoethylpyridine or N,N-dimethylethylenediamine in either metal-free reactions or in the presence of Pd2+ or Cu2+. The X-raycrystal structures of two metal derivatives of H2daddn have been determined.Crystals of [ PdL(N,)](in which L is the monoanion formed by proton loss from a phenolic group in the mono-Schiff basefrom H,daddn and 2-aminoethylpyridine) are monoclinic, space group P2,/c, with a = 11.220(1), b =12.91 0(2), c = 14.521 (2) A and = 92.540(9)"; at convergence R = 0.030 for 3398 reflections[ / > 2cs(/)], The Pd is essentially square planar with one N,- ligand, L acting as a tridentatechelating ligand which has a pronounced fold. The intact phenolic OH is hydrogen-bonded to theadjacent deprotonated and co-ordinated phenoxy centre. Crystals of [Cu(daddn) (en)]=MeOH (en =ethylenediamine) ale orthorhombic, space group Pbca, with a = 14.51 5(2), b = 16.596(3) and c =16.406(3) A; at convergence R = 0.046 for 11 58 reflections [/ > 30(/)].An approximately squareO,N, arrangement around the Cu is provided by a bidentate daddn2- on one side and a bidentateethylenediamine 011 the other; the molecules are present in pairs in which a phenoxide atom in onemolecule is weaklb bonded [Cu 9 0 2.848(12) A] to the Cu in its neighbour.Complexes of binucleating ligands which provide an accessiblebridging site where a variety of species can be introduced showunusual co-ordination chemistry ' including catalytic activity.2Models of complexes of the general type 1 constructed aroundthe 1,8-dihydroxynaphthalene nucleus reveal a geometry in theregion of Y and Z conducive, we believe, to enhanced efficiencyin the catalysis of the hydration of nitriles to carboxamides,compared with earlier systems;, in particular, we anticipatemore facile release of the carboxamide product from the bi-nuclear site, the bottleneck in the earlier catalytic cycle.2We have therefore been investigating the chelating ability ofvarious appropriately 2,7-disubstituted-l,8-dihydroxynaphth-alenes, some results of which are reported here. Related ligandsbased on the 2-substituted- 1,8-dihydroxynaphthalene nucleusand some of their complexes have been described by Fenton andco-workers.Results and DiscussionOur work is based on the building block 2,7-diacetyl-1,8-dihydroxy-3,6-dimethylnaphthalene 2, H,daddn, which hasbeen reported previously4 and for which an improved synthesisis described here.The BF3-catalysed rearrangement of 1,8-di-acetoxy-2-acetyl-3,6-dimethylnaphthalene afforded the diboroncomplex daddn(BF,), 3. Chelation of both acetyl oxygens, asin 3, is indicated by the fact that the band of highest frequencyin the 1600-1700 cm-' region of the IR spectum is found at1610 cm-', significantly lower than the v(C=O) band for any ofthe derivatives reported here in which one or both of the acetylgroups are unco-ordinated (1695-1 660 cm-'). Hydrolysis of thediboron complex in aqueous acidic methanol gave H,daddn.* Supplenietitur?. data available: see Instructions for Authors, J. Chem.Soc.. Dalroti Trans., 1992, Issue 1, pp. xx-xxv.Nnn-SI unit emplojvd: eV 2 1.6 x 10-19 J.Prior isolation of the 1,s-diacetoxy compound proved to beunnecessary and a very convenient route to H,daddn isprovided by the direct reaction of the readily available 2-acetyl-1,8-dihydroxy-3,6-dimethylnaphthalene with BF,*Et,O inacetic anhydride followed by hydrolysis with acid in aqueousmethanol.Attempts to isolate solid di-Schiff base ligands related to 1from the condensation of H,daddn with two equivalentsof either 2-(aminomethy1)pyridine (amp) or 2-(aminoethy1)-pyridine (aep) or N,N-dimethylethylenediamine gave only themono-Schiff bases.Examination by 'H NMR spectroscopy ofthe reaction in CDCI, between H,daddn and amp (1:2proportions) revealed that, in solution also, the reactionproceeds only as far as the mono-Schiff base formation. The twoCH, singlets in the 'H NMR spectrum of H2daddn (6 2.49, 3-and 6-CH3, 6 2.68, 2- and 7-CH3CO-) upon addition of twoequivalents of amp were replaced within minutes at roomtemperature by four singlets at 6 2.78,2.90,2.99 and 3.06; at thesame time the singlet at 6 6.85 due to the 4- and 5-aromaticprotons was replaced by two singlets at 6 6.91 and 7.07.Roughlyhalf the amp remained unchanged. Attempts to push thereaction in favour of the di-Schiff base by heating the solution,by adding an excess of amp and/or by adding catalytic amountsof CF,CO,D all failed, the above features of the mono-Schiffbase remaining essentially unchanged in the 'H NMR spectrum.Attempts to use metal ions to promote formation of di-Schiffbase complexes of the type 1 yielded, like the metal-freereactions, only mono-Schiff base products.By condensationof H,daddn with the appropriate amine in the presence ofPd" and the appropriate anion the complexes represented in 4were isolated. The structure of 4c, [PdL(N,)] {HL = 2-acetyl-l,8-dihydroxy-3,6-dimethyl-7-[2-(2-pyridyl)ethyliminoethyl]-naphthalene} determined by single-crystal X-ray diffraction isdescribed below. We concentrated here mainly on Pd" becausethis seemed to us the metal of choice for complexes of the type 1whose potential catalytic properties provided the primemotivation for the work, but IR analysis of solids isolate3084 J. CHEM. SOC. DALTON TRANS. 19920 OH OH 01352x z4a 1 CI4b 2 CI4~ 2 N36from similar reactions with Cu" suggested again that onlymono-Schiff base complexes were formed.It is not clear to uswhy these systems are so reluctant to give di-Schiff bases, forthe first acetyl group clearly reacts readily with the aboveprimary amines. To add to this mystery the di-primary aminesethylenediamine and propylenediamine condense readily withboth acetyl groups of H,daddn.Reactions of H,daddn with ethylenediamine in methanolgives a yellow crystalline solid, for which analytical, IR andmass spectral evidence are consistent with the 2:2 macrocyclictetra-Schiff base structure 5 (the compound was too insolublefor NMR analysis). The macrocycle 5 and the related acyclic di-Schiff base from one ethylenediamine (en) and two H,daddnunits have been referred to briefly by other worker^.^ Since wewere unable to isolate any pure complexes from attemptedinsertion of Cu" or Pd" into the preformed macrocycle weinvestigated the alternative approach of a template synthesisof the metal complexes, for which purpose [Cu,(daddn),],presumed to have the structure 6, was prepared as a precursorfrom reaction of H,daddn with Cu(O,CMe), in methanol.X-Ray crystallography would be required to establish thestructure of this product with certainty but suitable crystalshave eluded us.Reaction of [Cu,(daddn),] with 2 equivalentsof ethylenediamine in methanol yielded initially blue-greencrystals of the mononuclear complex [Cu(daddn)(en)] in whichthe diamine and the diketone are present unconnected by Schiff-base links, as was established by the single-crystal X-raydiffraction study described below.After prolonged heating ofthe reaction mixture the initially formed crystals of[Cu(daddn)(en)] gradually redissolved to give other productsnone of which was isolated in pure form.Crystal Structure of [PdL(N,)].-The asymmetric unit of[PdL(N,)] 4c consists of a single molecule. The atomic arrange-ment and numbering scheme are presented in Fig. 1, the atomicFig. IschemeMolecular structure of [PdL(N,)] showing atom numberingTable 1 Fractional atomic coordinates for the non-hydrogen atoms of[PdL(N,)] with estimated standard deviations (e.s.d.s) of the lastsignificant figure given in parenthesesX0.838 16(2)0.798 4(2)0.830 2(2)0.766 9(5)0.871 3(3)0.756 O(3)0.921 O(3)0.91 3 O(3)0.910 8(3)0.856 3(4)0.864 9(4)0.889 3(4)0.906 4(4)0.897 6(3)0.9 1 7 9( 3)0.806 O(4)0.665 3(3)0.618 2(4)0.611 6(3)0.484 7(3)0.396 9(3)0.440 O(3)0.513 3(3)0.464 8(3)0.534 7(4)0.479 O(5)0.659 313)0.739 3(4)0.778 9(4)0.7 10 O( 3)0.637 6(3)0.658 2(3)Y0.076 2 l(2) 0.390 45(2)Z0.086 5(2)- 0.006 4(2)- 0.076 9( 3)0.068 8(2)0.213 7(2)-0.062 5(2)-0.117 8(2)- 0.176 6(3)- 0.020 6(3)-0.025 O(4)0.063 7(4)0.155 4(4)0.156 O(3)0.251 7(3)0.290 4(3)0.239 7(3)0.348 6(3)0.169 4(3)0.171 2(3)0.225 l(3)0.1 14 9(3)0.059 6(2)0.005 4(3)- 0.049 4( 3)-0.104 7(4)-0.051 7(3)-0.110 l(3)-0.215 6(3)- 0.002 O(3)0.054 6(2)0.104 O(2)0.523 4( 1)0.681 O(2)0.899 O(2)0.254 l(2)0.372 8(2)0.406 3(2)0.471 7(2)0.531 3(2)0.207 7(3)0.113 l(3)0.066 O(3)0.1 13 3(3)0.209 O(2)0.266 l(3)0.309 3(3)0.419 2(2)0.412 l(3)0.485 5(2)0.498 2(2)0.432 6(2)0.567 5(2)0.631 5(2)0.705 7(2)0.767 6(2)0.846 3(3)0.757 4(2)0.824 7(3)0.796 4(3)0.684 4(2)0.618 8(2)0.539 8(2)coordinates in Table 1 and selected interatomic distances andangles in Table 2.Only one of the naphthol groups [0(1)] isdeprotonated and this together with the adjacent imine nitrogen[N(2)] and the pyridyl nitrogen [N(l)] chelates the Pd. Aroughly square arrangement around the Pd is completed by co-ordination of a terminal nitrogen [N(3)] of the monodentateazide ion. Metalkionor distances are unexceptional in the range2.005(2) to 2.033(3) A.Steric repulsion between the methyl groups C(9) and C(12),which would be extreme if the imine were coplanar with thenaphthalene, is most likely responsible for a marked fold in themolecule such that the average metal co-ordination plane isinclined at 54.5" to the average naphthalene plane.The iminecarbon atom [C(8)] and the attached methyl carbon [C(9)] aredisplaced 0.318 and 1.348 8, respectively to the side of thJ. CHEM. SOC. DALTON TRANS. 1992Table 2 Selected interatomic distances (A) and angles (") for[PdL(N,)] with e.s.d.s in parentheses *Pd-O( 1 )Pd-N( 1 )Pd-N( 2)Pd-N(3)O(l)-C(23)0(2)-C(2 1 )O( 3)-C( 19)N( 1 )-C( 1 )N( 1 )-C(5)N(2)-C(8)O( 1)-Pd-N( 1 )O( 1 )-Pd-N( 2)O( I )-Pd-N( 3)N( 1 )-Pd-N( 2)N( 1)-Pd-N( 3)N(2)-Pd-N( 3)Pd-O( 1 )-C( 23)Pd-N(1)-C( 1 )Pd-N( 1 )-C( 5)Pd-N(2)-C( 7)Pd-N( 2)-C( 8)C(7)-N(2tC(8)Pd-N( 3)-N( 4)N(3)-N(4bN(5)N(1 )-C(5)-C(6)C(4)-C( 5)-C( 6)C( 5)-C(6)-C( 7)N( 2)-C( 7)-C(6)N(2)-C( 8)-C(9)N(2)-C( 7)2.005(2)2.033(3)2.01 l(3)2.026(3)1.322(4)1.353(4)1.189(5)1.343( 5)1.342( 5)1.480(5)1.290(5)177.4( 1)86.8( 1)94.0( 1)91.1(1)88.1( 1)179.2(2)116.2(2)120.3( 3)119.3(2)119.0(2)118.7(3)124.6(2)174.6( 3)1 16.9(3)122.6(3)113.1(3)112.4(3)119.4(3)1 22.1 (2)N(2)-C(8)-C(10)C(S)-C(S)-C( 10)C(8)-C(lO)-C(ll)C(8kC( 10)-C(23)C( 10)-C( 1 1 )-C( 12)C( 13)-C( 14)-C( 15)C( 15)-C( 16)-C( 17)C(15)-C(16)-C(18)C( 16)-C( 1 8)-C( 19)C(19)-C(18)-C(21)O(3)-C( 19)-C( 18)0(3bC(19)-C(20)C( 18)-C( 19)-C(20)0(2)-C(21bC(18)O( 2)-C(2 1)-C(22)C(2 1 )-C(22)-C(23)O(1 )-C(23kC(10)O( 1 )-C(23)-C( 22)1.195(4)1.152(4)1.500( 5)1.5 1 3( 6)1.504(5)1.47 l(5)1.5 1 O( 5)1.507(6)1.500(5)1.496(6)122.5(3)120.6(3)119.5(3)123.1(3)12 1.4(2)120.0(3)1 19.0( 3)120.6(3)118.5(3)122.3(3)120.6(3)117.1(3)116.9(2)122.4(2)122.7(2)1 23.3( 2)117.5(2)1 17.9(3)* Naphthalene and pyridine rings: C-C distances are in the range1.35 1.44 A, average e.s.d.ca. 0.005 A, internal bond angles for thenaphthalene and pyridine rings are in the range 117.6-122.5", averagee.s.d. ca. 0.3 ..4)Fig. 2 Molecular structure of [Cu(daddn)(en)] showing atomnumbering schemenaphthalene plane remote from the Pd while the imine nitrogen[N(2)] is 0.231 A on the opposite side.The co-ordinatednaphthol oxygen [0( l)] is also displaced from the naphthaleneplane in the direction of the Pd by 0.276 A.The flexible N(2)-C(7)-C(6)-C(5) chain allows the pyridinering to be inclined at 36.6" to the metal co-ordination plane andto be approximately perpendicular (89.4') to the naphthaleneplane.The intact hydroxy group, 0(2)-H(02), is hydrogen bondedt o the adjacent deprotonated and co-ordinated naphthoxideatom O( 1 ) with an 0(1) O(2) separation of 2.594 A[0(2)-H(02) 0.83(4) A, O(1) H(02) 1.88(4) A]; this isvery similar to the N N separation of 2.60 A in protonated3085Table 3 Fractional atomic coordinates for the non-hydrogen atomsof [Cu(daddn)(en)] with e.s.d.s of the last significant figure given inparentheses *X-0.005 15(9)-0.104 l(5)0.051 4(6)0.078 6(5)0.247 4(6)0.035 4(8)0.016 2(7)0.083 8(7)0.158 7(7)0.166 9( 7)0.101 O ( 8 )0.023 3(6)-0.121 O(8)-0.066 8(4)-0.231 O(5)- 0.046 2(8)- 0.127 4(6)- 0.060 9( 7)0.274 7(8)0.227 6(0)- 0.260 O(7)- 0.207 6(8)0.248 6(8)-0.193 l(7)-0.076 3(7)- 0.020 9( 7)0.014 3( 13)Y0.393 30(7) -0.038 91(6)0.425 O(5) -0.1 17 7(4)0.336 5(5) -0.134 7(5)0.340 3(4) 0.031 5(4)0.447 2(4) 0.046 3(4)0.194 6(4) 0.1 19 5(5)0.572 7(5) 0.160 3(4)0.184 4(6) -0.012 2(5)0.387 8(6) 0.158 ! ( 5 )0.347 3(6) 0.111 8(7)0.308 6(6) 0.149 5(6)0.309 5(6) 0.236 3(6)0.347 3(6) 0.280 4(6)0.385 3(5) 0.245 7(6)0.421 l(6) 0.293 9(6)0.459 5(6) 0.261 6(6)0.463 4(6) 0.175 3(6)0.431 5(6) 0.124 5(6)0.303 3(8) 0.030 9(7)0.263 2(8) 0.100 6(6)0.466 2(7) 0.068 2(7)0.505 5(7) 0.136 3(6)0.271 9(6) 0.279 9(6)0.494 4( 7) 0.317 3(6)0.404 2(6) - 0.202 7(6)0.327 6(6) -0.198 3(6)0.129 9(9) 0.045 l(9)* The atoms of the methanol molecule are designated C(19) and O(5).Table 4 Selected interatomic distances (A) and angles (") for[Cu(daddn)(en)] with e.s.d.s in parentheses *Cu-N( 1)CU-N (2)cu-O( 1)cu-O(2)C(2)-0(1 1C( 10)-O( 2)C( 12)-0(3)C( 14)-0(4)N( 1 )-Cu-N(2)N( l)-CU-O( 1)N( 1 )-Cu-0(2)N(2)-Cu-O( 1)N(2)-Cu-0(2)O( 1)-Cu-O(2)Cu-N(2)-C( 18)cu-O( l)-C(2)Cu-O(2)-C( 10)C( 1 O)-C(9)-C( 14)C(2)-C( 1)-C( 10)C( 1 )-C( 10)-O(2)C(9)-C( 10)-0(2)C( 1 )-C( 2)-O( 1 )C(3)-C(2)-0(1)2.003(7)2.008(8)1.894(7)1.886(7)1.325( 13)1.3 1 2( 12)1.214( 15)1.231( 14)84.9(4)167.5(3)90.8(3)89.8(4)94.2(3)107.9(6)127.1(6)126.9(6)1 17.6(7)125.0(7)121.6(7)122.5(7)116.2(7)175.5(4)I 17.9(7)N(l)-C(17)N(2tC(18)C(9)-C( 14)C(8)-C( 16)C(13)-C(14)C(3)-C( 12)C(4tC( 15)C( 17)-C( 18)C(2)-C(3)-C( 12)C(4)-C(3)-C( 12)C(3)-C(12)-C( 11)C(3)-C( 12)-0(3)C( 1 1)-C( 12)-0(3)C(3)-C(4)-C( 15)C(5)-C(6FC(7)C(7)-C(S)-C( 16)C(9)-C( 8)-C( 16)C(8)-C(9)-C( 14)C(9)-C( 14)-C( 13)C(9)-C( 14)-0(4)C( 13)-C( 14)-O(4)N( 1)-C( 17)-C( 18)N(2)-C( 1 8)-C( 17)1.492( 12)1.487( 13)1 SO1 (1 5)1.3 8 1 ( 14)1 SO1 (1 5)1.487( 15)1.519( 15)1.506(14)120.9(8)119.1(8)119.8(8)119.8(8)120.4( 8)122.0( 8)122.2(7)119.8(8)1224 8)1 19.8(7)120.5(8)120.0(8)119.5(8)107.2(7)109.1(7)* Naphthalene rings: C-C distances are in the range 1.35-1.44 A,average estimated e.s.d.ca. 0.01 A, bond angles are in the range116-124", average e.s.d. ca. 0.8".proton sponge,6 1,8-bis(dimethylamino)naphthalene, which cor-responds to a very strong hydrogen bond.*The acetyl group which failed to form a Schiff base is twistedaround the C( 18)-C( 19) bond so that the C(20)-C( 19)-0(3)* We are indebted to one of the referees for suggesting that the apparentstrength of this hydrogen bond could be responsible for restricting thetemplate condensation to mono-Schiff base formation3086 J. CHEM. SOC. DALTON TRANS. 1992Fig.3respond to the Cu-O(2') and Cu' m m - O(2) bonds of length 2.85 ADimeric association in [Cu(daddn)(en)]. Broken lines cor-plane is almost perpendicular to the naphthalene unit; stericrepulsion from the adjacent methyl group C(17) is probablylargely responsible for this twisting.Crystal Structure qf [Cu(daddn)(en)]*MeOH.-The molecu-lar geometry and atom numbering scheme for [Cu(daddn)(en)]are shown in Fig. 2. Tables 3 and 4 provide atomic coordinatesand selected interatomic distances/angles respectively. Theasymmetric unit contains one molecule of the complex and onemolecule of solvation. A daddn2- ion chelates the Cu throughO( 1) and O(2) on one side of the metal and ethylenediamine ischelated on the other side so that N(1), N(2), 0(1) and O(2) areclose to coplanar.Copper-donor distances are normal andin the range 1.886(7) to 2.008(8) A. Angles at Cu range from84.9(4) to 94.2(3)'.The complex molecules appear in centrosymmetric pairs[centre of symmetry at (O,O,O)], a phenoxide atom in onemolecule [0(2)] providing a long 'axial' bond of 2.848( 12) 8, tothe Cu in the other so that the co-ordination geometry isessentially square pyramidal as shown in Fig. 3. The Cu isdisplaced 0.1 10 8, from the average plane of N( 1),N(2),0( 1),0(2)towards the attached phenoxide in the associated molecule. Themean donor atom plane is inclined at 9.5" to the meannaphthalene plane.The two acetyl groups are oriented so that their oxygens areon opposite sides of the naphthalene; O(3) and C(13) are located0.974 and 0.932 8, respectively on the side of the naphthaleneremote from the associated molecule and O(4) and C(11) are0.771 and 0.798 8, respectively on the opposite side.Again, stericrepulsion by the adjacent methyl groups is probably responsiblefor this twisting.Atom O(2) is displaced 0.155 8, from the mean naphthaleneplane towards the Cu of the associated molecule while 0(1)is displaced 0.261 8, on the opposite side to produce anO(1) - . . O(2) bite distance of 2.768(13) 8,.The methanol of solvation is hydrogen bonded to the non-bridging phenoxide, O( 1) with an 0 0 separation of2.757(12) 8,.ExperimentalNMR spectra were recorded on JEOL FX-100 or FX-90Qspectrometers, IR spectra as KBr discs on a JASCO A302spectrophotometer and electron impact (EI), positive-ion massspectra on VG Micromass 7070F and JEOL AX 505H GC-MSinstruments.Elemental analyses were performed by theMicroanalytical Service, University of Queensland, St. Lucia,Australia and by the Microanalytical Service, University ofOtago, Dunedin, New Zealand.2-Acetyl-1,8-dihydroxy-3,6-dimethylnaphthalene was pre-pared from 3-acetyl-6-methyl- 1 -oxacyclohex-5-ene-2,4-dione(Aldrich) by the method of Bethel1 and Maitlar~d.~ G,(CDCI,)2.41 (3 H, s, CH, of aryl), 2.61 (3 H, s, CH, of aryl), 2.72 (3 H, s,COCH,), 6.67 ( 1 H, s, aryl H), 6.86 (2 H, s, aryl H), 10.18 ( 1 H, brs, OH) and 17.46 ( 1 H, br s, OH). Gc(CDCI,) 22.0, 25.3 (CH, ofaryl), 32.0 (COCH,), 111.0, 112.6, 113.0, 117.4, 121.3, 133.4,138.4, 143.9, 158.0, 168.9 (10 x aryl C) and 204.4 (C=O).1,s-Diacetoxy-2-acetyl-3,6-dimethylnaphthalene was prepared asdescribed in the literature.' G,(CDCl,) 2.12 (3 H, s, CH,), 2.17(3 H, s, CH,), 2.19 (3 H, s, CH,), 2.32 (3 H, s, CH,), 2.77 (3 H, s,CH,), 6.31 (2 H, s, aryl H) and 6.77 (1 H, s, aryl H).Preparations.-2,7- Diacetyl- 1,8-dihydrox~~-3,6-dimethylnaph-thalene (H,daddn) 2. Addition of BF,-Et,O (48%, 7.4 g,52 mmol) to a solution of 2-acetyl-1,8-dihydroxy-3,6-dimethyl-naphthalene (2.96 g, 12.9 mmol) gave a bright red solutionwhich was stirred at ca. 120 "C for 10 min. After the mixture hadcooled to room temperature the yellow crystals of the diboroncomplex 3 which had separated were collected, washed withglacial acetic acid and could be recrystallised from chloroform,although this step was unnecessary (2.58 g, 5479, m.p.192-194 "C (Found: C, 52.5; H, 3.9; F, 20.5. cl6Hl4B2F4o4 requiresC, 52.2; H, 3.8; F, 20.6%). m/z (+EI, 15 eV) 348 ( M - F, 5),328 ( M - 2F, 5), 300 (loo), 285 (43), 258 (34), 243 (14) and2 16 (40%).The diboron complex 3 was converted to H,daddn, 2, inessentially quantitative yield by heating for 1 h in suspensionin boiling methanol-aqueous hydrochloric acid (10%) (10: 3)giving a yellow crystalline solid which could be recrystallisedfrom ethyl acetate although this was not necessary (Found:C, 70.6; H, 6.0%; accurate mass, m/z 272.1048 (Mf). C,6H1604requires C, 70.6; H, 5.9%; M + 272.1048). G,(CDCl,) 2.49 (6 H, s,CH,), 2.68 (6 H, s, COCH,), 6.85 (2 H, s, aryl H) and 14.13 (2 H,s, OH of aryl).G,(CDCl,) 20.6 (CH, of aryl), 31.5 (COCH,),11 1.0, 119.1, 121.2, 135.8, 136.7, 157.2 (aryl C) and 203.6 (GO).m/z (+ EI, 70 eV) 272 ( M + , 85), 257 (loo), 239 (95), 115 (10) and43 (22%).2- Acetyl- 1,8-dihydroxy-3,6-dimethy1-7-[(2-dimethylamino)-ethyliminoethyflnaphthalene. A solution of H,daddn (0.0562 g,0.2 1 mmol), N,N-dimethylethylenediamine (0.0424 g, 0.48mmol) and toluene-p-sulfonic acid (0.0118 g, 0.06 mmol) inethanol (4 cm3) was heated under reflux for 15 h, after whichtime the volume was reduced at atmospheric pressure untilyellow crystals started to separate. After the mixture had cooledand had been standing for several hours the crystals werecollected and washed with ethanol (0.059 g, 82%), m.p.162-164 "C (Found: C, 70.0; H, 7.7; N, 8.0%; accurate mass, m/z342.1945 (Mf). C20H26N203 requires C, 70.2; H, 7.7; N, 8.2%;M + , 342.1943). G,(CDC13) 2.33 [6 H, s, N(CH,),], 2.45 (3 H, s,CH,),2.50(3 H,s,CH,),2.62 (3 H,s,CH,),2.66(3 H,s,CH,),3.59 (2 H, t, J, 5.9, CH,), 3.66 (2 H, t, J, 5.9, Hz, CH,), 6.44 (1 H,s, aryl H) and 6.61 (1 H, s, aryl H). G,(CDCl,) 20.0 (CH,), 20.9(CH,), 26.0 (CH,), 32.4 (CH,), 43.1 (CH,), 45.4 "(CH,),],57.5 (CH,), 109.8, 113.8, 117.0, 117.3, 122.7, 136.1, 138.5, 140.0,161.5, 171.6 (aryl C), 180.2 and 204.6 (C=O/C=N). m/z (+EI,70 eV) 342 (M', l), 220 (26), 205 (loo), 145 (1 1) and 57 (39%).2- Acetyl- 1,8-dihydroxy-3,6-dimethyl-7-[ 2-( 2-pyridyl)ethyl-iminuvtlzy~naphthalene, HL. The procedure used was closelyanalogous to that above for the preparation of the N,N-dimethylethylenediamine mono-Schiff base.S"(CDC1,) 2.78 (3H, s, CH,), 2.90 (3 H, s, CH,), 2.99 (3 H, s, CH,), 3.06 (3 H, s,CH,), 5.33 (2 H, s, CH,), 6.91 (1 H, s, aryl H), 7.07 (1 H, s, arylH), 7.50-8.99 (m, CH of pyridyl). G,(CDCl,) 20.2 (CH,), 20.9(CH,), 26.1 (CH,), 32.4 (CH,), 50.0 (CH,), 110.2, 113.7, 117.2,119.9, 121.4, 122.9, 136.1, 137.2, 138.5, 140.3, 149.8, 154.8, 161.2,172.2 (aryl C), 180.8 and 204.6 (C=O/C=N). mjz (+ EI, 70 eV)320 ( M ' , loo), 285 (46), 214 (51), 133 (46), 93 (60) and 92H,daddn-ethylenediumine mucrocycle 5. Ethylenediamine(0.0287 g, 0.48 mmol) was added to a suspension of H,daddn(0.1031 g, 0.38 mmol) in methanol (7 cm3) heated under reflux.The suspended solid dissolved over a period of 15 min toproduce a clear orange solution.After several further min at theboiling point compound 5 started to precipitate as amicrocrystalline yellow solid. The mixture was heated under(53%).reflux for 1 h and was then allowed to cool. The solid waJ . CHEM. SOC. DALTON TRANS. 1992 3087Table 5 Crystal data and details of crystal structure determinationsCompoundFormulaMCrystal systemSpace grouph, AUiA< IADlUIA3zDJgcm 'D,:gcm 'Crystal dimensions(distance in mm from the centroid)F(000)p(Mo-K%)/cm-'Absorption correction28 range/"Range of I?, k, ITotal no. of reflectionsNo. of unique reflectionsNo. of unique reflections used in refinementFunction minimizedWeighting scheme parameters g , k inNo.o f variablesFinal RFinal R'Max. shift/e.s.d. for non-hydrogen atomGoodness of fit, SMaximum residual electron density/e k3(min., max. transmission coefficients)RinrM' = k/[02(Fo) -k SF,'][Cu(daddn)(en)]C H ,CUN O,*CH ,OH426.0OrthorhombicPbca (no. 61)14.5 15(2)16.596(3)16.406(3)3952(2)81.4321.433( 5)- + ( - I 11)0.064- +(1 -1 1)0.050+ ( I 1 -1)O.OSO?(I f f)0.057175210.990.8764,0.94512.0-40.00 f h < 15, -2 < k < 17, -2 < I < 17495625790.01931158 [I 2 30(1)]0.001, 1.2034C4lFOI - lFd22640.0460.0470.01 11.1390.32CPdUN3)I522.0MonoclinicP2 /c (no. 14)12.9 lO(2)14.52 1 (2)92.540(9)2101.3(8)41.6561.653(5)f ( l 0 0)0.093k(0 1 1) 0.093c2 3H 2 3N 5O 3 Pd11.220(1)k(0 -1 1)O.OlO10648.750.8484,0.88752.0-55.0627848120.01413398 [ I > 20(1)]O.OO0 23, 1.0575- 1 < h < 1 4 , - l < k < 1 6 , - 1 8 < / < 1 8Cw(lJ-oI - lJ-cl)z3050.0300.0300.00 11.3630.53collected and washed with methanol (0.0420 g, 37%) (Found: C,72.6; H, 6.9; N, 9.6.C3,H4,N404 requires C, 72.9; H, 6.8; N,9.5',,). nil: ( + E I , 15 eV) 592 (M', loo), 296 (lo), 230 (30), 188(6), 84 (54) and 55 (1 8%).Merd C'ornpfc.urs.-[ PdL'Cl] 4a { HL' = 2-acetyl-1,8-di-/ i ? ~ r l r o . ~ ~ ~ - 3 , 6 - ~ i m c t / i ~ ~ f - 7 - [ ( 2-pyridyI)methyliminoethyll-nuphthdenc,I. A solution of 2-(aminomethy1)pyridine (0.0560 g,0.52 mmol) and H,daddn (0.0652 g, 0.24 mmol) in methanol ( 5cm3) was heated under reflux 0.5 h and then 1,8-diazabicyclo-C5.4.01-undec-7-ene (0.0390 g, 0.26 mmol) in methanol (ca.1cm3) was added. The resulting solution was added to a boilingsolution of PdC1, (0.0453 g, 0.26 mmol) and LiCl(O.0311 g, 0.74mmol) in methanol. Yellow crystals of [PdL'Cl] 4a formedimmediately and were collected and washed with methanol(0.0690g, 57%) (Found: C, 52.6; H,4.2;N, 6.0. C22H,,CIN,0,Pdrequires C , 52.5; H, 4.2; N, 5.6%). v(C=O) 1682 and v(C=N) 1615cm-'.[PdLCl] 4b. A mixture of PdCl, (0.0456 g, 0.257 mmol),lithium chloride (0.0253 g, 0.597 mmol) and H,daddn (0.0339 g,0.124 mmol) suspended in methanol (10 cm3) was heated underreflux until all the solid had dissolved and then 2-(aminoethy1)-pyridine (0.0325 g, 0.266 mmol) was added.The volume wasreduced by boiling at atmospheric pressure until crystallisationcommenced. The yellow needles of 4b were collected after themixture had been allowed to cool and were washed withmethanol (0.0632 g, 987;). v(C=O) 1685 and v(C=N) 1625 cm-'.[ PdL( N 3)] 4c. A solution of 2-(aminoethy1)pyridine(0.01 83 g, 0.15 mmol) and H,daddn (0.0176 g, 0.065 mmol) inacetonitrile ( 5 cm3) was heated to boiling for 5 min. Theresultant orange solution was added to a boiling solution ofPd(MeCO,), (0.0293 g, 0.13 mmol) dissolved in the minimumof acetonitrile. The mixture was heated gently for a furtherlOmin, cooled to room temperature and sodium azide (0.0142 g,0.218 mmol) dissolved in methanol ( 5 cm3) was added.Theclear orange solution upon cooling and standing yielded redprisms suitable for X-ray diffraction studies. The crystals of 4cwere collected and washed with methanol (0.0313 g, 92%).GH[(CD,),SO]2.23 (3 H,s,CH3),2.33(3 H,s,CH3),2.41(3 H,s,CH,), 2.49 (3 H, s, CH,), 3.59 (2 H, br t, CH,), 3.84 (2 H, br t,CH,), 6.86 (1 H, s, aryl H) and 7.48-8.38 (4 H, m, aryl H).v(C=O) 1695, v(C=N) 1625 and v(N3) 2050 cm-'.[Cu(daddn)(en)]. Copper(rr) acetate monohydrate (0.4463 g,2.34 mmol) in boiling methanol (10 cm3) was added to H,daddn(0.58 16 g, 2.13 mmol) in boiling methanol (10 cm3) whereupon abrown microcrystalline solid separated. The mixture wasmaintained at the boiling point for 30 min and the suspendedsolid presumed to be 6 was collected and washed with methanol(0.5910 g, 83%) (Found: C, 58.6; H, 4.5.C3,H2&u2O8 requiresC, 57.6; H, 4.2%). v(C,,,,-0) 1550 and v(C=O) 1660 cm-'.When ethylenediamine (0.0085 g, 0.14 mmol) was added to asuspension of 6 (0.0422 g, 0.063 mmol) in boiling methanol(3 cm3) the solid dissolved to produce a dark green solution.The volume of the solution was reduced to ca. 5004 by boiling atatmospheric pressure whereupon dark blue-black octahedralcrystals of [Cu(daddn)(en)] separated. The crystals werecollected and washed with methanol after the mixture had beenallowed to cool (0.0235 g, 47%) (Found: C, 54.3; H. 5.8; N, 6.7.C1 ,H,,CuN,O, requires C, 54.9; H, 5.6; N, 7.1 ",).Crystal Structure Analyses.--Blue-black crystals of [Cu-(daddn)(en)] suitable for diffraction studies were obtained bysuspending [Cu,(daddn),] 6 in a methanolic solution con-taining an approximately equimolar amount of ethylenediamin3088 J.CHEM. SOC. DALTON TRANS. 1992in a glass tube of diameter 0.4 cm and maintaining the mixtureat 45 "C in a water-bath for 24 h. The crystals were approxi-mately octahedral in shape.Cubic red crystals of [PdL(N,)] 4c were grown directly froma reaction mixture which was allowed to stand for 24 h.Intensity data were measured at 294°C using an Enraf-Nonius CAD-4F single-crystal, automatic diffractometer withmonochromated Mo-Kx radiation (h = 0.710 69 A) and 0-28scan technique. Accurate cell dimensions and the orientationmatrix were determined by a least-squares procedure using theangular settings of 25 carefully centred reflections.Crystal dataand details of the data collections are listed in Table 5.Neither set of data showed any significant variation in intensityduring the course of data collection. Corrections for Lorentz,polarization and absorption effects were applied,'",' but nocorrection was made for extinction. The scattering factors usedfor atomic C, H, N and 0 were those incorporated into theSHELX 76 program,' while those for atomic palladium andcopper were taken from ref. 8b and corrected for both real andimaginary anomalous dispersion effects.8cThe positions of the majority of the non-hydrogen atoms forboth structures were indicated by the SHELXS 86 program ' Ousing the direct method routine.The remaining non-hydrogenatoms were indicated in subsequent difference maps producedby the SHELX 76 program.' The structures were refined using afull-matrix least-squares procedure with anisotropic thermalparameters applied to all non-hydrogen atoms. The differencemaps indicated the positions of all hydrogen atoms. Thepositions of all the hydrogen atoms bonded to carbon andnitrogen atoms were constrained at geometrically estimatedpositions with C-H and N-H bond lengths of 1.08 and 1.01 A,respectively. The hydrogen atom bonded to the unco-ordinatednaphthol oxygen atoms, H(02), in the complex, [PdL(N,)]was included in the model at the position indicated by thedifference map. Isotropic thermal parameters were applied tothe hydrogen atoms of the copper complex such that a commonthermal parameter was applied to all methyl hydrogen atoms.Asimilar procedure was used for all the methylene, aromatic andamine hydrogen atoms. In the case of the palladium complex, anisotropic thermal parameter was applied to each aromatichydrogen atom and a common thermal parameter was appliedto the hydrogen atoms of each of the methylene and methylgroups. The refinement was continued until convergence toyield the values of R, R', g and k listed in Table 5, together withthe values of the maximum residual electron densities.Crystallographic diagrams were prepared using the ORTEPprogram.' 'Additional material available from the Cambridge Crystallo-graphic Data Centre comprises H-atom coordinates, thermalparameters and remaining bond lengths and angles.References1 R. Robson, Znorg. Chim. Acfa, 1982, 57, 71; 1984, 85, 195; T. E.Crossley, P. Davies, M. Louey, R. Robson and T. N. Huckerby,Znorg. Chim. Acta, 1984, 85, 199; M. G. B. Drew, P. C. Yates,J. Trocha-Grimshaw, K. P. McKillop and S. M. Nelson, J. Chem.Soc., Chem. Commun., 1985, 262; M. Louey, C. J. McKenzie andR. Robson, Inorg. Chim. Acta, 1986,111, 107.2 C. J. McKenzie and R. Robson, J. Chem. SOC., Chem. Commun., 1988,112.3 M. Vidali, R. Graziani, P. A. Vigato, U. Cassellato, D. E. Fentonand C. M. Regan, Inorg. Chim. Acta, 1980, 38, 85; P. A. Vigato,U. Cassellato, M. Vidali, R. Graziani, D. E. Fenton and C. M. Regan,Znorg. Chim. Acta, 1979,32, L27; U. Cassellato, D. Fregona, S. Sitran,P. A. Vigato and D. E. Fenton, J. Less-Common Metals, 1986, 122,249.4 J. Casabo, F. Teixidor, A. Llobet and L. Escriche, Rev. R. Acad. Cien.Exactas, Fix Nut. Madrid, 1984,78, 399; F. Teixidor, L. Escriche, A.Llobet and J. Casabo, Abstracts of Third European Symposium onMacrocyclic Compounds, University of Stirling, 1984.5 J. R. Bethel1 and P. Maitland, J. Chem. SOC., 1962, 3751.6 M. R. Truter and B. L. Vickery, J. Chem. SOC., Dalton Trans., 1972,395.7 J. C. Overeem and G. J. M. Van der Kerk, Recl. Trav. Chim. Pays-Bas, 1964,83, 1005.8 J. A. Ibers and W. C. Hamilton (Editors), International Tables forX-Ray Crystallography, Kynoch Press, Birmingham, vol. 4; (a) p. 61,(b) p. 100, (c) p. 149.9 G. M. Sheldrick, SHELX 76, Program for Crystal StructureDetermination, University of Cambridge, Cambridge, 1976.10 G. M. Sheldrick, SHELXS 86, Program for Crystal StructureDetermination. Crystallographic Computing 3, eds. G. M. Sheldrick,C. Kruger and R. Goddard, Oxford University Press, 1985, p. 175.11 C. K. Johnson, ORTEP, Report ORNL-3794, Oak Ridge NationalLaboratories, Oak Ridge, TN, 1965.Received 29th June 1992; Paper 2/034 19