摘要:

J. CHEM. SOC. DALTON TRANS. 1984 237 1 Studies of Pendant-arm Macrocyclic Ligands. Part 2.' Comparison of the Nickel(ll), Copper(ii), and Zinc(l1) Complexes of I I -( 2'-Dimethylaminoethyl)-1,4,7,11 -tetra-azacyclotetradecane, a Pyridine Analogue, and a Related New Tetra-aza Macrocycle, 1 'I -Methyl-l,4,7,1 I -tetra-azacyclotetradecane Nathaniel W. Alcock, Peter Moore," and Colin Pierpoint Department of Chemistry and Molecular Sciences, University of Warwick, Coventry CV4 7AL The complexes of Ni2+, Cu2+, and Zn2+ with two closely related pendant-arm penta-aza macrocycles 1 1 - (2'-dimethylaminoethyl) -1,4,7,11 -tetra-atacyclotetradecane, L1, and 7- (2'-dimethylaminoethyl) - 3,7,11,17-tetra-azabicyclo[l1.3.1] heptadeca-1 (1 7),13,15-triene, L2, have been characterised spectroscopically. The square-planar complex of the protonated ligand L1, [Ni( HL')] [C10413, previously reported to be a mixture of two isomers, has been found to isomerise in hot aqueous solution to give two further isomers.Six-co-ordinate thiocyanato-complexes of formula [Ni(Ll)(NCS)]CIO, and [Ni(HL1)(NCS)2]C104 have been isolated. For the protonated copper(i1) complex of the ligand (Ll) (but not Lz), a temperature-dependent equilibrium of the type [Cu(L1)]2+ + H+ [Cu(HLl)]s+ exists in aqueous solution, and a variable-temperature visible spectroscopic study shows that, at 298.2 K, K = (2.2 f 0.3) x 1 O3 dm3 mo1-l and AG* = -1 9.05 f 0.29 kJ mol-1. lsomerisation of the protonated copper complex was not observed. The complexes of formula [Zn(L)][NO& (L = L1 or L2) were found to be single isomers which do not isomerise even at elevated temperatures. l3C N.m.r.studies show that in [Zn(L1)] macrocycle is asymmetric whereas in [Zn( L Z ) ] [NO3I2 the macrocycle is in a symmetric configuration. The new, related macrocycle, 1 1 -methyl-l,4,7,11 -tetra-azacyclotetradecane, L3, and its complexes with Ni2+, Cu2+, and Zn2+ have been prepared. 13C N.m.r. studies show that the diamagnetic, planar complex [Ni(L3)] [C104]2 is a single symmetric species, whereas [Zn(L3)] [NO3lZ is a 1 : 2 mixture of a symmetric and an asymmetric species. the In Part 1 we reported the synthesis of two new quinqueden- tate pendant-arm macrocycles L' and L2 and their isomor- phous complexes of Ni2+ and Cu2+, [M(L)][ClOrI2 (L = L', M = Ni or Cu). Both ligands form trigonal-bipyramidal complexes in which the pendant arm occupies one of the three trigonal co-ordination sites, as revealed by a crystal structure determination of the nickel(1t) complex.The complexes of Ni2 + and Cu2+ were found to undergo reversible protonation to form square-planar complexes in which the pendant arm is protonated and non-co-ordinating [reaction (i)]. [M(L)I2+ + H+ @ [M(HL)13+ (9 Now we report further studies of these systems, together with the synthesis of the zinc complexes of the ligands L' and L2. The thermodynamic parameters associated with equilib- rium (i) have been determined from a variable-temperature pH study of the copper(II) complex, and thiocyanato-com- plexes of [Ni(L)I2+ and [Ni(HL)I3+ have been isolated. We have prepared a further new related quadridentate tetra-aza macrocycle, L3, together with its complexes of Ni2+, Cu2+, and Zn2 + for comparison with those of the macrocycles L1 and L2.Results and Discussion Nickel(11) Complexes.-As shown previously, there are eight possible isomers for the protonated square-planar species [M(HL)][Cl0,I3 (L = L'; M = metal ion), Figure 1; (A) and (G), and (C) and (E) are enantiomeric pairs. The 13C n.m.r. spectrum of [Ni(HL')P+ previously revealed the pres- ence of two of these isomers, one of which was assigned structure (E) by comparison with the crystal structure of [Ni(L')]'+, and the other assigned any of the symmetric struc- tures (B), (D), (0, or (H). Upon heating [Ni(HL1)I3+ in aqueous solution at ca. 80 "C L' R = CH,CH,NMe, L2 L3 R =Me Figure 1.Schematic representation of the eight isomers of [Ni(HL1)13+ or [Ni(L3)I2+. The pendant-arm position of L1 and the NMe group of L3 are circled, and + or - represents the position either of these groups, or of the NH groups, with respect to the macrocyclic plane. (C)/(E) and (A)/(G) are enantiomeric pairs. For [Ni(HL2)I3+ there are four isomers: (A)/(C), (B)/(D), (E)/(G), and (F)/(H)2372 J. CHEM. SOC. DALTON TRANS. 1984 I I I I I I 1 I I I hlnm 400 50 0 6 00 700 800 900 1000 1100 Figure 2. Visible spectral changes recorded at 5-min time intervals during the isomerisation of [Ni(HL1)][C104]3 (2.7 x 1O-j mol dm-3; l-cm path length cell) at 323 K in water. The peak at ca. 970 nm decreases, and the one at cu. 480 nm increases with time Table 1."C N.m.r. data (S/p.p.m.) a for [Ni(HL1)][C104]3 and [Ni(L3)J[CIO4JZ (for tentative assignments refer to Figure I) Table 2. Magnetic susceptibilities at 298 K in CD3NOZ solution * Complex XIPe Complex XIPB [ N i( H L' )] [ C104]34 * * "i(L1)l[C1041z 3.65 [CU(L')][CIOJ~ 2.26 [ N i( H L')] [C104]3 Diamagnetic [Cu( H L')] [C104]3 2.1 0 Isomer (B) 22.9,' 45.6," 46.0,' 47.7, 49.5, 50.1, 51.8, 55.6 [Ni(L')(NCS)]CIO, 3.27 [Cu(L2)l[C10,12 2.35 Isomer (D) or (H) (cu. 85%) 23.8(2),' 44.3(1)," 45.8(2),' [Ni(HL2)][C1O4I3 Diamagnetic [CU(L~>][CIO~]~ 1.89 46.7(2), 47.8(2), 52.4(1), [ Ni(L3)] [C10412 Diamagnetic 53.5(2), 54.9(2) ~Ni(Lz)1rc~0412 3.57 [Cu(HLZ)][CIO,]3 2.1 1 * Determined by the method of D. F. Evans, J. Chem. Soc., 1959, 2003. Isomer (C)/(E) (cu. 10%) 20.5,' 23.7,' 44.6,' 44.9, 45.6, 49.5, 50.1, 50.6, 51.2, 51.8, 55.3, 55.5, 56.1 "i(L3)l[C10,1~" " I n CD3NOz at 298 K with SiMe, as internal reference.bSome additional resonances for a minor species (< 5%) were observed, [Ni(HL')]'+, at S 24.0,26.6,45.4,48.9, and 51.9 p.p.m. ' C-CHz-C. At equilibrium after heating in aqueous solution. -NCHzCHzN+HMez. -NCH3. 23.5,' 43.5,h 48.2, 49.3, 54.8, 61.7 -CHzN+HMer. ' -N+H(CH& for several hours, isomerisation occurs to give a mixture of three isomers. The reaction was monitored by visible spec- troscopy (Figure 2) which revealed the presence of an inter- mediate. I3C N.m.r. studies show that a major new symmetric species (ca. 85%) is formed, leaving cu. 10% of isomer (E) and a new minor asymmetric species (<5%) tentatively assigned t o (AMG).We have recently shown how donor solvents assist nitrogen inversions in 1,4,8,11 -tetramethyl- 1,4,8,11 -tetra-azacyclo- tetradecanenickel(ii) {[Ni(L4)I2+} complexes.' A complex with a structure analogous to (B) is known to form when L4 is added t o Ni2+, and this 'all-four-up' set of nitrogen configurations has also been shown to form for the nickel(i1) complex of the 2,12-C-dimethyl analogue of the ligand Lz.' Starting from (B), successive single nitrogen inversions can give rise to the other isomers as shown in the Scheme. If we assume by analogy with previous studies that structure 11 11 11 Scheme. (B) is initially present, a plausible explanation of our ob- servations is that a symmetric structure (D) or (H) is formed by a single NH inversion from (B) or (C)/(E) respectively.Tentative assignments of the 13C n.m.r. data on this basis are given in Table 1. Proof of these assignments must await isolation of the isomers and characterisation by X-ray crystal- lography. The 13C n.m.r. spectrum of the square-planar complex [Ni(L3)][C10412 shows the presence of a major symmetric species, but a distinction between structures (B), (D), (F), or (H) could not be made from the chemical shifts (Table 1). Reaction of the trigonal-bipyramidal [Ni(L)]' + and square- planar [Ni(HL)]'+ complexes (L = L1 or Lz) with sodium thio- cyanate gives the six-co-ordinate complexes [Ni(L)(NCS)] + and [Ni(HL)(NCS),]+ respectively. The visible spectra of these complexes (Table 3) show them to be pseudo-octahedral, and the magnetic moment of [Ni(L')(NCS)]CIO, (Table 2) is as expected for such a geometry.There is no displacement of the pendant arm in [Ni(L)Iz+ even with a large excess ofJ. CHEM. SOC. DALTON TRANS. 1984 2373 1 I 1 I I 1 70 60 50 40 30 20 6 /p. p. m. Figure 3. 'H Decoupled I3C n.m.r. spectrum of [Zn(L1)][NO3l2 I I I I 1 100 75 50 25 0 6 /p.p.m. Figure 4. 'H Decoupled "C n.m.r. spectrum of [Zn(L3)J[NO3I2 thiocyanate ion. The bis(thiocyanate) adducts of the proton- ated complexes have two nitrile i.r. bands (e.g. for the complex of L' at 2 105 and 2 080 cm-'), and by comparison with recent results for [Ni(L4)(NCS),] 3*4 they probably have a trans geometry ; [Ni(L4)(NCS)2] was originally reported to have a cis structure,3 but by comparison with a related crystal struc- ture is now believed to have a trans c~nfiguration.~ Zinc(11) Complexes.-The macrocycles L', L2, and L3 all re- act with Zn[N03]2-6H20 to give the complexes [Zn(L)][NO&.The 13C n.m.r. spectrum of [Zn(L')][NO,], (Figure 3) shows the presence of a single asymmetric species. This is supported by the 'H n.m.r. spectrum which reveals the N-methyl groups to be non-equivalent (in DzO, 6 2.50 and 2.66 p.p.m.). This is only possible if the pendant arm is co-ordinated to the Zn2+. Assuming that this complex forms by the same mechanism as that for the nickel(l1) complex, it is most likely that it has structure (C)/(E). The complex in D20 is inert and undergoes very slow proton exchange as shown by three clearly visible N-H resonances at 6 4.05, 4.16, and 4.40 p.p.m.with couplings to adjacent protons. The ''C n.m.r. spectrum of [Zn(L2)][N03]2 is analogous to that of the nickel(1i) complex, showing a single symmetric species to be present. This must be either isomer (B)/(D) or (F)/(H). Again, the N-H protons are in slow exchange in D20 solution.2374 J. CHEM. SOC. DALTON TRANS. 1984 1 aJ u C 0 -? 0.5 d 0 n -. 5 00 600 700 800 900 1000 1100 A/nm Figure 5. Visible spectral changes associated with equilibrium (i) for [CU(HL')][CIO,]~ (4.92 x rnol dm-3, 1-cm path length cell) in 0.1 mol dm-3 LiC104 at eight temperatures in the range 288.4-328.5 K. The absorbance at 820 nm decreases and that at 560 nm increases with increase in temperature Table 3. Visible spectra of complexes 3L,,,./nm (4dm3 mol-' cm-') h Complex In CH3NO2 "i(L1)I[C10412 368(sh), 584(42), 1 245(18) [Ni(HL1)][C104]3 464( 122) [Ni(HL1)][C104]3 482( 129) I I I I I I I I I I I I :Ni(L')(NCS)]ClO, 572(16.5), 91q12.5) 'Ni(HL1)(NCS),]C1O4 572(21), 948(25) ni(Lz)l [Cl04lz 372(140), 568(44), 808(12), 1375(15) :Ni(HLz)][C104]3 469( 152) :Ni(L2)(NCS)]C104 512(29), 756(16) :Ni(HLZ)(NCS),]NCS 530(27), 765(33) :Ni( L3)] [C104]2 480( 146) :cu(L')I [C10412 625(5), 772(262) :c~(L2)I[c~0112 570( 163), 760(5) :c~(L3)1[clo41z 5 36( 1 66) :CU(HL')][CIO~]~ 542( 158) :CU(HL')][CIO~]~ 548(168.5) In HzO 375(78), 584(36), 1 240(14) 370(20), 458(12.5), 588(10), 976(13) 375(24), 480(33), 560(s), 1 220(4) 348(18), 560(16), 758(10) 350( 12), 475(91.6) 640(5), 768(198) 558(143) 595(153.5), 780(5) 565( 174) 546( 1 8 1) After isomerization.Aqueous LiC104 (0.1 rnol dm-9 solution plus HClO,.Aqueous LiC104 (0.1 rnol dm-7 solution. The "C n.m.r. spectrum of [Zn(L3)][NOJZ is shown in Figure 4. Two isomers are present, one symmetric and one asymmetric, in a ratio 1 : 2. This ratio does not change on heating an aqueous solution for several hours; the complex shows two N-Me 'H resonances at 6 2.40 and 2.45 p.p.m. in the ratio 1 : 2. The N-H protons are also in slow exchange with D20. Copper(n) Complexes.-The complex [CU(L')][CIO,]~ was found previously to be isomorphous with [Ni(L1)][C104]2, and like the nickel(rr) complex undergoes protonation to give [CU(HL')][CIO~]~ [reaction (i)].' However, unlike the nickel complex, no isomerisation was detected in aqueous solution at elevated temperatures. One further difference is that equil- ibrium (i) lies to the right only in strongly acidic solutions.The visible spectra of [Cu(HL')]'+ were recorded in 0.1 mol dm-3 LiC104 between 288 and 328 K, and these spectra are shown in Figure 5. Isosbestic points are evident at 610 and 445 nm. The absorbances at 820 and 900 nm were fitted by equations (ii)-(iv), based on equilibrium (i). K = exp(-AG"/RT) = [CU(HL)~+]/([CU(L)~+][H+]~ (ii) (iii) [Cu], = [CU(L)~+] + [Cu(HL)'+] A = &cut[C~L2+] + &CUHL[CU(HL)3 + 1 (iv) Values of the absorption coefficient for the protonated complex, &CUHL, were determined at very low pH where [CuL2+] = 0; E C ~ H L = 27.85 and 13.2 dm3 mol-I cm-' at 820 and 900 nm respectively. Values of absorbances, A, at the two wavelengths as a function of temperature were fitted simul- taneously by non-linear regression analysis using equations (ii)-(iv), treating AG* (or K at 298.2 K) and the absorption coefficient of [Cu(L)]* + as unknown parameter^.^ This gave K = (2.2 f 0.3) x lo3 dm3 mo1-', AG* = - 19.05 f 0.29 kJ mol-I, and cCuL = 166.6 & 7.1 and 181.3 & 7.1 dm3 mol-' cm-I at the two wavelengths.At a total copper concentration of 5 x and [Cu- (HL)2+] = 6.38 x rnol dm-' at 298.2 K; i.e. there is 87.2% closure of the pendant-arm ring at this concentration, showing the greater affinity of Cu2+ for the pendant Me,N group compared with a proton. The analogous complex, [Cu(HL2)13+, was not observed to ring-close in this way, and the copper chelate ring formed by the pendant arm of the macrocycle L2 is, therefore, less stable than that formed by the macrocycle L'.mol dm-3, [CU(L)~+] = 4.36 x Experimental Materials and Methods.-All chemicals used were of the highest available purity. 'H-Decoupled, natural-abundance,J. CHEM. soc. DALTON TRANS. 1984 2375 n.m.r. spectra were recorded either at 100.6 MHz using a Bruker WH400 Fourier-transform spectrometer, or at 22.6 MHz using a Bruker WH90 Fourier-transform spectro- meter. 'H N.m.r. spectra were recorded using a Bruker WH400 Fourier-transform spectrometer or a Perkin-Elmer (model R34) 220-MHz spectrometer. 1.r. spectra were recorded using a Perkin-Elmer (model 580B) spectrometer equipped with an internal reference. U.v.-visi ble spectra were recorded with a Shimadzu (model 365) spectrophotometer. Mass spectra were recorded using a Kratos (model MS80) instrument.Com- pounds L', L2, [Ni(L)][C104]2 (L = L' or L'), [Ni(HL)]- [Cl0J3 (L = L1 or L2), [CU(L~)][C~O~]~, [CU(HL')][C~O~]~, and N0O'-tris(methylsulphonyl)diethanolamine were pre- pared as previously described.' Preparation of the Ligand L3.-A solution of NN-bis(3-p- tolylsulphonylaminopropyl)methylamine (43.5 g, 96 mmol) in NN-dimethylformamide (dmf) (250 cm3) was stirred under nitrogen during the addition of sodium hydride (4.6 g, 192 mmol). When gas evolution had ceased the solution was heated to 110 "C and a solution of NO0'-tris(methylsulphony1)- diethanolamine (32.6 g, 96 mmol) in dmf (200 cm3) was added dropwise over 2 h. The resulting solution was heated at 110 "C for 12 h and then poured into an equal volume of water.The whole of the solvent was removed by evaporation under re- duced pressure; the resulting viscous brown oil was dissolved in concentrated H2SO4 (150 cm3) and the solution heated at 100 "C for 24 h. After cooling the solution was poured into ethanol (300 cm3) and diethyl ether (500 cm3) added. The resulting dark brown precipitate was collected by filtration and dissolved in the minimum amount of distilled water. The pH of the solution was adjusted to ca. 10 with 20% NaOH (as) followed by extraction with dichloromethane (5 x 100 cm3). The combined extracts were dried (MgS04), filtered, and evaporated to leave a yellow oil. Distillation (kugelrohr apparatus) gave a colourless oil which solidified on standing to give the ligand L3, 1 l-methyl-1,4,7,1 l-tetra-azacyclotetra- decane (4.5 g, 21 mmol), b.p.120-122 "C at 0.05 mmHg, (ca. 6-7 Pa), m.p. 38-40 "C, in ca. 22% yield. N.m.r., 'H (CDC13), 6 1.71 (4 H, quintet), 2.13 (3 H, s), 2.40 (4 H, t), and 2.72 p.p.m. (15 H, m); I3C (CD3N02), 6 28.0 (2 C-CH2-C), 41.6 (NMe), 47.3 (2C), 47.4 (2C), 49.7 (2C), and 57.6 (2C) p.p.m. 1.r. (thin film) : 3 290 cm-I (N-H). Electron-impact mass spectrum; m/z 214 ( M + ) . Isomerisation of [Ni(HL1)][C10413.-The complex [Ni- (HL')][C104]3 (1 10 mg, 0.17 mmol) was dissolved in distilled water and the solution heated at 70 "C overnight. Removal of the solvent gave a quantitative yield of isomerised material. [ Ni(L1)(NCS)]C104.-The complex [Ni(L1)][C1O4I2 (0.1 g, 0.i9 mmol) was stirred in ethanol during the addition of a solution of NaSCN (0.022 g, 0.19 mmol) in ethanol.The pale purple precipitate was collected by filtration, washed with ethanol then diethyl ether, and dried in vacuo to give [Ni(L')- (NCS)]ClO, (91 mg, 0.18 mmol) in ca. 95% yield (Found: C, 35.9; H, 6.8; N, 16.3. C15H33C1N6Ni04S.HZ0 requires C, 35.6; H, 7.0; N, 16.6%). 1.r. (Nujol mull): 3 330, 3 300 (N-H), 2 074 (SCN), and 1 100 cm-I (C104). [Ni(HL')(NCS)2]CI04.-The complex [Ni(HL')][ClO,], (50 mg, 80 pmol) was stirred in ethanol during the addition of NaSCN (18.6 mg, 160 pmol). The resulting pale purple pre- cipitate was filtered off, washed with ethanol and diethyl ether, then dried in vacuo to give [Ni(HL1)(NCS),]C104 (42 mg, 74 pmol) in ca. 93% yield (Found: C, 34.45; H, 6.1; N, 17.4. C16H34CIN7Ni04S2*H20 requires C, 34.05 ; H, 6.4; N, 17.4%).1.r. (Nujol mull): 3 310, 3 265, 3 210 (N-H), 2 105, 2 080 (NCS), and 1 096 cm-' (c104). [Ni(L2)(NCS)]C104.-The complex [Ni(L2)][C10412 (30 mg, 53 pmol) was stirred in ethanol during the addition of Na- SCN (6.5 mg, 55 pmol). The resulting purple precipitate was filtered off, washed with ethanol-diethyl ether, and dried in vucuo to give [Ni(L2)(NCS)]C104 (25 mg, 48 pmol) in ca. 90% yield (Found: C, 41.3; H, 5.9; N, 15.9. C ~ B H ~ ~ C ~ N ~ N ~ O ~ S requires C, 41.4; H, 6.0; N, 16.1%). 1.r. (Nujol mull): 3 330, 3 310 (N-H), 2 080 (SCN), 1 605, 1 582 (pyridine), and 1 110 cm-' ( 0 , ) . [Ni(HL')(NCS),]NCS.-The complex [Ni(HL2)][C104]3 (20 mg, 30 pmol) was stirred in ethanol during the addition of NaSCN (10.6 mg, 90 pmol) in ethanol. The pale purple pre- cipitate was filtered off, washed with ethanol-diethyl ether and dried in vacuo to give [Ni(HLZ)(NCS),]NCS (15 mg, 28 pmol) in ca.93% yield (Found: C, 42.7; H, 5.7; N, 19.9. CzoHJ2NsNiS3-H20 requires C, 43.1 ; H, 6.15; N, 20.1%). 1.r. (Nujol mull): 3400, 3 200 (N-H), 2082 (SCN), 2060(sh), 1 603, and 1 578 cm-l (pyridine). [Ni(L3)][C104]2.-l 1 -Methy1-1,4,7,11 -tetra-azacyclotetra- decane L3 (0.25 g, 1.2 mmol) was dissolved in ethanol and added to a solution of [Ni(dmSO)6][C104]2 (dmso = dimethyl sulphoxide) (0.85 g, 1.2 mmol) in ethanol. The resulting orange precipitate was filtered off, washed with ethanol-diethyl ether, and dried in vacuo to give [Ni(L3)][C104]2 (0.50 g, 1.10 mmol) in ca. 90% yield (Found: C, 28.1; H, 5 . 5 ; N, 11.7. C11H26C12- N4NiOe requires C, 28.0; H, 5.55; N, 11.9%).1.r. (Nujol mull): 3 205, 3 190 (N-H), and 1 080 cm-' (c104). 'H N.m.r. (CD3- NOz): 6 1.76 (4 H, m), 2.12 (2 H, m), 2.40 (2 H, m), 2.65 (8 H, m), 2.70 (3 H, s), 2.98 (2 H, m), 3.13 (2 H, qnt), and 3.50 p.p.m. (3 H, N-H). [C~(L~)l[C10~]~.-The ligand L2 (140 mg, 0.46 mmol) was dissolved in ethanol and added to a solution of CU[C~O~]~* 6H20 in ethanol. The resulting blue-purple precipitate was filtered off, washed with cold ethanol, and dried in vacuu to give [Cu(L2)][CIO,l2 (0.15 g, 0.27 mmol) in ca. 60% yield. 1.r. (Nujol mull): 3 580 (0-H), 3 240 (N-H), 1 615, 1 590 (pyridine), and 1 110 cm-' (c104). [CU(HL~)][C~O,]~.-T~~ complex [Cu(L2)][C1O4], (100 mg, 0.176 mmol) was stirred in ethanol during the addition of a slight excess of HC104 (70% aqueous).The resulting purple precipitate was filtered off, washed with ethanol, and dried in vacuu to give [CU(HL~)][C~O~]~ (0.1 g, 0.15 mmol) in ca. 85% yield (Found: C, 29.1 ; H, 4.8 ; N, 9.7. CliH32C13C~N5012-2H20 requires C, 29.0; H, 5.1; N, 9.9%). 1.r. (Nujol mull): 3 560 (0-H), 3 240 (N-H), 1 615, 1 585 (pyridine), and 1 100 cm-I (C104). [CU(L~)][CIO,]~.--I 1 -Methyl-l,4,7,11 -tetra-azacyclotetra- decane L3 (0.1 g, 0.47 mmol) was dissolved in ethanol and stirred during the addition of CU[CIO~]~.~H~O (0.173 g, 0.47 mmol). The resulting purple precipitate was filtered off, washed with cold ethanol and diethyl ether, then dried in t'acuo to give [Cu(L3)][C104], (0.19 g, 0.4 mmol) in ca. 85% yield (Found: C, 27.95; H, 5 . 5 ; N, 11.8.C11H26C12N401 requires C, 27.7; H, 5.5; N, 11.75%). 1.r. (Nujol mull): 3 220 (N-H) and 1 090 cm-' (ClO,). [Zn(L1)][N03]2.-The ligand L' (50 mg, 0.18 mmol) was dissolved in ethanol and Zn[N03]2*6H20 (54.8 mg, 0.18 mmol) in ethanol was added. Addition of diethyl ether gave a white precipitate which was filtered off, washed with ether, and2376 J. CHEM. SOC. DALTON TRANS. 1984 dried in vacuo to give [Zn(L1)][NOJ2 (80 mg, 0.17 mmol) in 94% yield (Found: C, 34.6; H, 7.0; N, 19.6. C14HJ3N706Zn*1 .5 H20 requires C, 34.8; H, 7.4; N, 20.1%). 1.r. (Nujol mull): 3 260 and 3 160 cm-I (N-H). [Zn(L2)][NOJ],.-The ligand L2 (50 mg, 0.16 mmol) was dissolved in ethanol and added to Zn[NO3I2*6H2O (48.6 mg, 0.16 mmol) in ethanol. The product was precipitated by addition of diethyl ether, filtered off, and dried in vacuu to give [Zn(L2)][N03]2 (74 mg, 0.15 mmol) in cu. 92% yield (Found: C, 41.1; H, 6.4; N, 19.6. C17H~iN706Zn requires C, 41.3; H, 6.3; N, 19.8%). 1.r. (Nujol mull): 3 280 cm-I (N-H). N.m.r. (DzO): 'H, 6 2.11 (4 H, m), 2.70 (6 H, s), 2.91 (4 H, m), 3.05 (4 H, m), 3.18 (4 H, m), 4.00 (2 H, d), 4.36 (1 H, d), 4.45 (1 H, t), 4.50 (1 H, m), 4.56 (1 H, m), 7.56 (2 H, d), and 8.14 p.p.m. (1 H, t); 13C, 6 22.6 (2 x C-CH2-C), 47.2 (2 C), 47.6 (2 C), 51.2 (1 C), 51.5 (NMez), 53.2 (2 C), 56.5 (1 C), 123.6 (2 P-C), 143.0 (y-C), and 154.2 p.p.m. (2 a-C). [Zn(L3)][N03]2.-This compound was prepared as des- cribed for L2, from the ligand L3 (0.4 g, 1.87 mmol) and Zn- [NOJ2*6H20 (0.56 g, 1.87 mmol) in ethanol: yield 0.75 g, 1.74 mmol, ca. 93% (Found: C, 32.9; H, 6.5; N, 20.6. CllHZ6- N,06Zn requires C, 32.7; H, 6.5; H, 20.8%). 1.r. (Nujol mull): 3 270 and 3 190 cm-' (N-H). Acknowledgements We thank Dr. E. H. Curzon for recording 400-MHz n.m.r. spectra, and the S.E.R.C. for financial support. References 1 Part 1, N. W. Alcock, R. G. Kingston, P. Moore, and C. Pier- 2 P. Moore, J. Sachinidis, and G. R. Willey, J. Chern. SOC., Chern. 3 E. K . Barefield and F. Wagner, Inorg. Chem., 1973, 12,2435. 4 E. K. Barefield, personal communication. 5 C. H. McAteer and P. Moore, J. Chem. SOC., Dalton Trans., point, J. Chem. SOC., Dalton Trans., 1984, 1937. Commun., 1983, 522. 1983, 353. Received 14th October 1983 ; Puper 3/1821

ISSN:1477-9226    

DOI:10.1039/DT9840002371

出版商:RSC    

年代:1984

数据来源: RSC