J . CHEM. SOC. DALTON TRANS. 1986 939Synthesis, Spectroscopic, and Structural * Studies of Dimethylthallium(iii)Complexes containing Heterocyclic Nitrogen-donor Ligands, including'TIC,N,O,' and 'TIC,O,' GeometriesAllan J. Canty and Karen MillsChemistry Department, University of Tasmania, Hobart, Tasmania, Australia 700 IBrian W. Skelton and Allan H. WhiteDepartment of Physical and Jnorganic Chemistry, University of Western Australia, Nedlands, W.A. 6009The complexes dimethyl [2- (pyridin-2-yl)imidazolato] thallium( HI), (2,2'- bi-imidazolato) bis[di-methylthallium(iii)], and their benzimidazolato-analogues are monomeric in chloroform.Dimethylthallium(iii) nitrate forms complexes of stoicheiometry [TIMe,L] NO, {L = 1,lO-phenanthroline, 4,4'-diethyl-2,2'- bipyridyl, N-methyl-2- (pyridin-2-y1)imidazole (pymim), bis-( pyridin -2-yl) methane [ (py),CH,], or bis(N-methylimidazol-2-yl) met hanol [ (mim),CH 0 HI},[TIMe,(terpy)] NO,-H,O (terpy = 2,2':6',2"-terpyridyl), and [ (TIMe,),( Et,terpy),] [NO,], (Et,terpy =4,4',4''-triethyl-2,2':6',2''-terpyridyl).Proton n.m.r. spectra of the nitrate complexes in methanolindicate co-ordination of the nitrogen-donor ligands to the dimethylthallium(iii) cation. The structuresof the (py),CH,, terpy, and Et,terpy complexes have been determined by single-crystal X-raydiffraction at 295 K and refined by least-squares methods to R 0.048,0.061, and 0.071 for 2 739,3 000, and 1 547 independent 'observed' reflections, respectively. The complexes have linear orislightlybent C-TI-C groups, with weak TI .N and/or TI 0 interactions in approximate equatorial planes.The (py),CH, complex has a dimeric, centrosymmetric, structure with nitrate groups weakly linkingtwo 'TIMe,{ (py),CH,}' groups to form [{TIMe,[ (py),CH,] (NO,)},] with 'TIC,N,O,' co-ordinationhaving TI N 2.658(9) and 2.666(9), TI 0 2.770(9)-2.915(10) A, and C-TI-Cl71.7I5)".opposite (py),CH,. The terpy complex has a tridentate ligand [TI N 2.620(10)-2.650(9) A] with3 water molecule and nitrate ion 2.932(12) and 3.250(19) A from thallium, and is thus formulated as[TIMe,(terpy) (H,O)] NO,, with a 'TIC2N302' environment having C-TI-C 169.6(6)' opposite terpy.The Et,terpy complex has two 'TIMe,( Et,terpy)' groups [C-TI-C 166( 1 )" opposite tridentate Et,terpy,TI N 2.61 (3)-2.66(3) A] linked by a 'TIMe,(NO,),' group [linear C-TI-C, TI 0 2.72(2)-2.85(3) A] to give the molecule [(TIMe,),( Et,terpy),( NO,),] possessing a two-fold axis and'TIC,N,O,' and 'TIC,O,' co-ordination environments.Crystal data: [{TIMe,[ (py),CH,] (NO,)},]monoclinic, space group P2,/c, a = 8.923(3), b = 22.535(8), c = 7.527(3) A, p = 96.78(3)", and2 = 2; [TIMe,(terpy) ( H,O)] NO, monoclinic, space group P2,/c, a = 9.779(3), b = 13.290(3),c = 14.380(4) A, p = 93.95(2)", and 2 = 4; [(TIMe,),( Et,terpy),( NO,),] tetragonal, space groupl4,/a, a = 15.71 5(6), c = 45.21 (1 ) A, and 2 = 8.Crystallographic studies of the interaction of dimethyl-thallium(r1I) with neutral donor ligands have revealed novelstereo~hemistries.'~ For the four complexes studied to datethe [TlMe,]+ moiety is linear in crown ether complexes[ 178( l), 177.5(4), or 180"],2-4 with the environment 'TIC,O,'involving weak T1 - 0 interactions [2.694(10F2.979(5) A]in the equatorial region,24 or slightly bent in [TlMe,(phen)]-C10, with the environment 'TIC N202' involving TI N[2.57(3) A] and T1 0 [2.88(3) A] in the equatorial regionand the C-T1-C angle [ 168(1)"] opposite the stronger thallium-1 ,lo-phenanthroline interaction.'As 1,lO-phenanthroline is a rigid ligand, and the cyclic crownethers are expected to favour strongly formation of six TI 9 0interactions, we have explored the interaction of [TIMe,] + withligands possessing more flexibility in their co-ordinationbehaviour. Thus, bis(pyridin-2-y1)methane [(py),CH,] andbis(N-methylimidazol-2-y1)methanol [(mim),CHOH] possessflexibility about the bridging carbon atom, and the ligands N-Supplementary data available (No.SUP 56469, 16 pp.): thermalparameters, H-atom parameters, ligand bond distances and angles,least-squares planes. See Instructions for Authors, J. Chem. SOC., DaltonTrans., 1986, Issue 1, pp. xvii-xx. Structure factors are available fromthe editorial office.[ biim 1'' [pyiml-methyl-2-(pyridin-2-yl)imidazole (pymim), 4,4'-diethyl-2,2'-bi-pyridyl (Et,bipy), 2,2':6',2"-terpyridyl (terpy), and 4,4,4"-triethyl-2,2':6',2"-terpyridyl (Et,terpy) are also expected to beflexible, 4.g. Et,terpy acts as a tridentate ligand to methyl-mercury(1r) in the solid state but as a bidentate ligand inmethan01,~'~ and bidentate co-ordination of terpy in the solidstate has been established crystallographically for [Ru(CO),-Br2(terpY)l.6 tt For other examples involving the proposal that terpy acts as auldentate ligand, largely from spectroscopic data, see refs.5 and 7940 J. CHEM. SOC. DALTON TRANS. 1986Table 1. Characterisation data for the complexes[T1Me,(Et,bipy)]N03[TIMe,(pymim)]NO,[TIMe, {(mim),CHOH )]NO,[TIMe,(terpy)]NO,-H,O[TIMe,(pybzim)][(TIMe,),biim][(TIMe,),bibzim]Analysis (%)" - C H N35.7 2.8 8.4(35.3) (3.0) (8.8)37.6 3.9 8.2(37.8) (4.4) (8.3)28.9 3.1 12.3(29.0) (3.3) (12.3)33.3 3.2 9.3(33.5) (3.5) (9.0)26.9 3.6 14.5(27.0) (3.7) (14.3)37.3 3.4 10.4(37.3) (3.5) (10.2)37.6 4.1 8.5(37.8) (4.2) (8.3)31.3 3.2 11.0(31.7) (3.2) (11.1)39.8 3.5 9.9(39.2) (3.3) (9.8)19.9 2.5 9.2(20.0) (2.7) (9.3)30.9 2.4 8.2(30.8) (2.9) (8.0)_-, ...-cm-'5505485 505605525445465245 34536528G(TIMe,) IZJ('H-Tl)ld1.04 420.81.01 420.41.28 42 1.6I .07 42 1.81.03 420.70.89 422.80.89 421.71.01 366.61.04 364.00.99 371.21.12 365.9Ligand9.17, 2, dd, H(2,9); 8.63, 2, dd, H(4,7);8.06, 1, s, H(5,6); 7.94, 2, m, H(3,8)/8.57, 2, d, H(6); 8.17, 2, s, H(3);7.38, 2, d, H(5); 2.81, 4, 9, CH,;1.33, 6, t, CH,#8.88,l,d, H(6); 8.22-8.1 1,2,m, H(3,4);7.63, 1, m, H(5); 7.46, 1, s, and7.31, 1, s, H(4'5'); 4.30, 3, s, CH,h8.47, 2, d, H(6); 7.78, 2, m, H(4);7.35, 2, d, H(3); 7.29, 2, m, H(5);4.31, 2, s, CH,'7.10, 2, d, and 6.90, 2, d, H(4,5);6.12, 1, s, CHOH; 3.73, 6, s, CH,'8.83, 2, d, H(6,6"); 8.51-8.43, 4, m,H(3,3',5',3"); 8.28, 1, m, H(4'); 8.13, 2,m, H(4,4"); 7.65, 2, m, H(5,5")k8.71, 2, d, H(6,6"); 8.41, 2, s, and8.37, 2, s, H(3',5', 3,3"); 7.56, 2, d,H(5,5"); 3.00, 2, q, CH',; 2.90, 4,9, CH, and CH",; 1.46, 3, t, CH',;1.38, 6, t, CH, and CH",'8.24, 1, d, H(3); 8.18, 1, d, H(6);7.76, 1, m, H(4); 7.18, 2, s, im;7.14, 1, m, H(5)"8.60, 1, d, H(3); 8.30, 1, d, H(6);7.85, 1, m, H(4); 7.69, 2, br, H(3',6');7.29, 1, m, H(5); 7.17, 2, m, H(4',5')06.92, 2, s7.59, 2, m, H(3,6); 7.18, 2, m,H(4,5)a Calculated values are given in parentheses. Nujol mulls, medium-weak absorption; [TIMe,]NO, has vaSym at 562w cm-'. Shifts in p.p.m.fromSiMe, in CD,OD (nitrate complexes) or CDCl, (other complexes); given as chemical shift, relative intensity, multiplicity; [TlMe,]NO, has G(TlMe,)1.05 and IZJ('H-TI)I 422.5 Hz in methanol.Broad resonances, with IZJ('H-203Tl)l and (2J(1H-205Tl)I not resolved (width at half-height ca. 20 Hz).J(H3,H4) = 8.2, J(Hz,H3) = 4.6, andJ(H2,H4) = 1.5 Hz. phen-H,O: 8.94, dd, H(2,9); 8.16, dd, H(4,7); 7.59, s, H(5,6); and 7.56, m, H(3,8); J(H3,H4) = 8.1, J(H2,H3) = 4.4, and J(H2,H4)= 1.7 Hz. J(H5,H6) = 5.1, Jc,hyl = 7.6 Hz. Et,bipy:8.50, dd, H(6,6'); 8.13, s, H(3,3'); 7.28, d, H(5,5'); 2.75, q, CH,; and 1.30, f , CH,; J(H5,H6) = 5.1,J(H4,H6) = 1.5, and Jethyl = 7.6 Hz. J(H5,H6) = 4.8. pymim: 8.59, ddd, H(6); 7.96, m, H(3); 7.83, m, H(3); 7.31, m, H(5); 7.17, d, and 7.06, d, H(4',5');and 4.02, s, CH,; J(H5,H6) = 4.8, J(H4,H6) = 1.6, J(H3,H6) = 0.9, and J(H4'H5') = 1 Hz.J(H3,H4) = 7.9 and J(H5,H6) = 4.3 Hz. (py),CH,:8.46,m, H( 6); 7.72, m, H(4); 7.32, d, H( 3); 7.24, m, H( 5); 4.3 1, s, CH ,; J( H ,H 6, - 4.5, J( H H4) = 7.9 Hz. J J( H4,H ') = 1 Hz. (mim),CHOH : 7.1 0, d, and 6.90,d, H(4,5); 6.1 1, s, CHOH; and 3.75, s, CH,; J(H4,H5) = 1.2 Hz. Ir J(H5,H6) = 5 Hz. terpy:8.65, m, H(6,6"); 8.60, m, H(3,3"); 8.36, d, H(3'3'); 8.02, m.H(4'); 7.97, m, H(4,4"); and 7.45, m, H(5,5"); J(H3,H4) ca. 8.0, J(H3'H4') = 7.9, and J(H5,H6) ca. 4.8 Hz. ' J(H5,H6) = 5.1 and J(H7,H8) = 7.6 Hz.Et,terpy: 8.53, d, H(6,6"); 8.43, s, H(3,3"); 8.18, s, H(3',5'); 7.34, m, H(53"); 2.86,9, (CH',); 2.82, q, (CH,, CH",); 1.38, t , CH',; and 1.35, t, (CH,, CH",);J(H5,H6) = 5.0 and Jclhr, = 7.7 Hz.Molecular weights in chloroform at 37 "C determined by osmometry, with concentration and calculated valuefor monomer in parentheses: [TIMe,(pyim)], 382 (31.9,379); [TlMe,(pybzim)], 413 (27.9,429); [(TIMe,),biim], 613 (44,601); and [(TlMe,),bibzim],714 (36.4 mmol dm-,, 701). " J(H3,H4) = 8.2 and J(H5,H6) = 4.8 Hz. J(H3,H4) = 8.1 and J(H5,H6) = 4.4 Hz.Spectra of free ligands in CD,OD are given in footnotes ( j - 1 ) for ligands forming nitrate complexes.To complement these studies we have re-examined phen as amodel bidentate ligand, and included more basic pyridine andimidazole donors derived by deprotonation of 2,2'-bi-imidazole(giving [biim]'-), 2-(pyridin-2-yl)imidazole (giving [pyim] - ),and their benzimidazole analogues.ResultsPreparation and Characterisation of Complexes.-The nitratecomplexes were obtained as colourless crystals on reaction ofdimethylthallium(m) nitrate with an equimolar quantity ofligand in acetone to give products of stoicheiometry[TIMe,L]NO,, except for the terpy complex which crystallisedas a monohydrate and the Et,terpy complex which formedcrystals of stoicheiometry [(T1Me2)3(Et3terpy)2][N03]3.The binuclear complexes [(TlMe,),L] [L = biim or 2,2'-bibenzimidazolate (bibzim)] were prepared by reaction ofdimethylthallium(rr~) iodide with an alkaline solution of theligands in water, and the complexes [TlMe,L) [L = pyim or 2-(pyridin-2-yl)benzimidazolate (pybzim)] were obtained on re-fluxing a suspension of the iodide with silver(1) derivatives of Lin dichloromethane followed by separation of insoluble AgI.The complexes have microanalysis and 'H n.m.r.spectraconsistent with the formulae presented, and the neutralcomplexes [(TlMe,),L] and [TlMe,L] are monomeric inchloroform (Table 1). The nitrate complexes exhibit vaSym(TIC2)at 560-544 cm-', slightly lower than for [T1Me,]NO3 (562cm-'), although similar to that for [TlMe,]CIO, (555 cm-');*binding to the more basic ligands present in the neutralcomplexes results in lowering of vasym(TlC2) to 536-528 cm-'.The nitrates have nitrate absorption(s) in the region 1 4 0 0 -1300 cm-', compared with intense and broad absorption at1450-1 300 cm-' for [TIMe,]N03, but the presence ofligand absorption in this region prevents precise assignmentof nitrate absorption(s) for most of the complexes.There appear to be no reports of stability-constant determinJ .CHEM. soc. DALTON TRANS. 1986 94 1ations for the interaction of dimethylthallium(r1r) with neutraldonor ligands, although constants for some anionic ligandshave been measured, e.g. log K 5.56 & 0.01 for the 2,4-pentanedionato complex.' Co-ordination of neutral ligands to[TlMe,]+, when present in 1 : 1 mole ratio in solution, has beendemonstrated for crown ether^^*^*'^ and nitrogen-donormacrocycles' ' by n.m.r. spectroscopy, and co-ordination bypyridine in acetonitrile is likely since [TlMe,(py)]ClO, may berecrystallised from acetonitrile.8If the complexes of neutral donor ligands reported here arepartially or substantially dissociated in solution, [TIMe,] + +L+[TIMe,L]+, then the 'H n.m.r.resonances will be aresult of averaging of the resonances for the species in solution.Thus, although G(TlMe,) and I2J('H-Tl)I are essentially un-changed from the values for [TlMe,]N03 (Table l), it is ofinterest that, except for (mim),CHOH, the ligand resonancesare altered from the free-ligand values, indicating at leastpartial complex formation in methanol, e.g. downfield shifts of0.23-4.47 and 0-4.06 p.p.m. occur for the phen and (py),CH,resonances, respectively, and both upfield (0.06 p.p.m.) anddownfield (0.224.26 p.p.m.) shifts occur for Et,terpy.For the complexes of Et,bipy, terpy, and Et,terpy, changes inthe chemical shift difference between H(3,3') and H(5,5')(Et,bipy), and between H(3,3"), H(5,5"), and H(3',5') (terpy,Et,terpy) are clearly indicative of interaction with [TlMe,]+.Differences between these resonances for 2,2'-bipyridyls areknown to be sensitive to the interplanar angle between thepyridin-2-yl rings,' 2 * 1 which alters on protonation,' andinteraction with other electrophiles such as methylmercury(11)'~and dichloroplatinum(11)' ' also induces changes in the chemicalshift difference between H(3,3') and H(5,5').Thus, in thepresence of [TlMe,] + changes in these differences at least partlyreflect changes in the interplanar angle(s) from values for theligands in CD,OD [e.g. 80-100" for 2,2'-bipyridyl(s)] to othervalues resulting on co-ordination to [TIMe,]', e.g.for terpyA(3,3" - 5,5") alters from 1.09 to 0.8 1 p.p.m. and A(3,3" - 33')from 0.25 to 0.04 p.p.m. on interaction with [TlMe,]+.Although the 'H n.m.r. spectra of the nitrate complexesindicate co-ordination of the ligands in methanol, the ligands arenot necessarily chelated except for 1,lO-phenanthroline, as theyare flexible in their co-ordination behaviour.For the nitrate complexes bonding between [TlMe,]' andthe ligands in solution is clearly weak as G(TlMe,) andI2J( 'H-TI)( are essentially unaltered from the values for[TIMe,]', in contrast to the neutral complexes of thedeprotonated ligands, [(TlMe,),L] and [TIMe,L], for which adecrease of 50-60 Hz in IZJ('H-Tl)I on co-ordination isindicative of much stronger TI-N interactions.The couplingconstants obtained, 364-371.2 Hz, are similar to thoseobserved for related complexes of deprotonated pyrazoles, e.g.[(TlMe,(p-C3H,N2-N,N'))2] has I2J( 'H-Tl)I 376 Hz inC,D,.16 Thus, the n.m.r. spectra of these complexes, and theirmonomeric behaviour in chloroform, are consistent with thestructures shown, involving quadridentate [biim12- and[bibzimI2- and bidentate [pyim] - and [pybzim] -.Structures of the (py),CH2, terpy, and Et,terpy Complexes.-Aspects of the molecular geometry of the complexes are given inTables 2 - 6 , and views of the structures in the Figure.The complexes have T1-C 1.97(4)-2.139( 13) A, similar toreported values for crown ether complexes and [TIMe,(phen)]-CIO, containing neutral donor ligands [2.097(9)-2.180(17)A],14 and the nitrogen-donor ligands are chelated withTI N distances 2.61(3)-2.666(9) A, within 3cr of the valuefor the phen complex, 2.57(3) A.' The (py),CH2 and Et,terpycomplexes have thallium nitrate distances of 2.72(2)-3.1 l(3) A, similar to the T1 0 distances in the crown ether[2.694( 10)-2.979(5) A]'" and perchlorate [2.88(3) A]'complexes.The terpy complex has a water molecule weaklyinteracting with thallium, 2.932(12) A, and a nitrate ion at adistance 3.250( 19) A, corresponding to that expected for a vander Waals or weak electrostatic interaction, ca. 3.36 A, usingPauling's radius for oxygen (1.4 A)" and Bondi's estimatedradius of 1.96 A for thallium." It is thus formulated asCT1Me,(terpy)(H,O)IN0,.Table 2.Specific crystallographic detailsComplexFormulaMCrystal systemSpace groupb/A 4PI"u pF(o(wPMoIcm- 'SpecimenimmAbsorption factor(min., max.)2em, I.. INoDJg ~ m - ~zNRR'C{TIMezC(PY)2CHzJ(No3)} 21(C13H16N303n)2933.4MonoclinicP2,lc; no. 148.923(3)22.535(8)7.527(3)96.78(3)1 503(1)2.062 dimers8801040.33 x 0.32 x 0.244.6, 12.2604 4162 7390.0480.056MonoclinicP2,Ic; no. 149.779( 3)13.290(3)1 4.3 8q4)93.95(2)1 864.5(8)1.9541048840.28 x 0.43 x 0.184.3, 8.8605 46230000.06 10.06345.2 1 (1)1 1 165(7)1.8185 840840.25 x 0.40 x 0.344.3, 8.5402 6191 5470.07 10.06942 J. CHEM. SOC. DALTON TRANS. 1986Figure. Structures of (a) [{T1Me2[(py)zCH,](N0,))z], (b) [T1Me2(terpy)(Hz0)JN0,, and ( c ) [(TIMe,),(Et,terpy),(NO,),]. projected normal tothe equatorial ‘planes’ in each case; 20”/, thermal ellipsoids are shown for the non-hydrogen atoms together with atom numbering.Hydrogen atomsare shown with an arbitrary radius of 0.1 AThe nitrate groups in the (py),CH, complex link two‘TlMe,((py),CH,}’ moieties to give a centrosymmetric dimer[(T1Me2[(py)2CH,](N03)~~] with a ‘TlC,N,O,’ co-ordin-ation environment. For the Et,terpy complex, two ‘TlMe,(Et,-terpy)’ moieties are weakly linked by a ‘TlMe,(NO,),’ group togive an aggregate of stoicheiometry [(TlMe,)?(Et,terpy),-(NO,),] having a two-fold axis and co-ordination environ-ments ‘TlC2N302’ and ‘TICz06.’In all three complexes the [TlMe,] + group is bent, with theC-T1-C angle 166(1)-171.7(5)” opposite the T1 N inter-actions, except for the ‘TlCz06* group in the Et,terpy complexwhere a symmetrical ‘TlO,’ donor set [Tl 0 2.72(2)-2.85(3) A] results in a linear [TlMe,]+ group.The pyridyl rings and nitrate groups are planar, withmaximum deviations from the mean planes observed for C(2) ofring c in the Et,terpy complex (-0.06 A) and for O(2) of thJ.CHEM. SOC. DALTON TRANS. 1986 943Table 3. Non-hydrogen atom co-ordinates for [{TIMe2[(py)2CH2](N0,))2]Feature Atom X Y Z X0.4 17( 1)0.458( 1)0.572( 1)0.651(1)0.609( 1)0.490(1)Y0.104 7(4)0.079 4(5)0.100 7(6)0.148 8(7)0.175 8(6)0.152 6(5)LO.Ml(1)0.153(2)0.065(2)0.132(2)0.287(2)0.364(1)0.058 09(2)0.065 2(6)0.041 4(6)0.429 19(5)0.174(2)0.688(2)0.178 24(5)0.045(2)0.287( 2)0.165( 1)0.03q 1 )O.O08( 1)0.1 32( 2)0.272(2)0.286( 1 )0.439( 1)0.175 4(4)0.200 2(5)0.259 O(5)0.295 l(5)0.272 3(6)0.21 1 5(5)0.181 6(6)0.47 1 ( 1)0.422( 2)0.389(2)0.405(2)0.450(2)0.480( 1)0.531(1)0.205( 1)0.301(1)O.O99( 1)0.21 7( 1)-0.082 l(5)-0.044 8(4)-0.067 4(4)-0.133 2(4)0.33 I( 1)O.M7( 1)0.420(2)0.282( 1)TaMe 4.Non-hydrogen atom co-ordinates for [TlMe,(terpy)(H,O)]NO,X Y z X-0.177( 1)- 0.039( 1)0.226(1)0.093( 1)0.050(2)0.150(2)0.283(2)0.3 15( 1)Y0.238( 1)0.235 q9)0.022 q7)- o.oO0 4(9)-0.095 3(11)-0.164 5(10)-0.140 2(11)- 0.047 7( 10)z0.052( 1)0.034 8(8)0.142 9(7)0.140 9(8)0.167 3(9)0.197 2( 10)0.199 5(10)0.171 7(10)0.308 23(4)0.258(2)0.395( 1)0.202 3q4)0.275( 1)0.137(1)0.093 91(3)0.2 19( 1)- 0.023( 1)0.156(1)0.019(1)-0.061(1)0.002(2)0.14 l(2)0.21 5( 1)0.045( 1)-0.006(1)- 0.22q 1 )- 0.142( 1)0.324 O(8)0.31 5( 1)0.382( 1)0.457( 1)0.- 1)0.397( 1)0.155 9(7)0.080 1 ( 10)0.078( 1)0. I52( 1)- 0.0 12 q7)-0.017 3(8)- 0.070 8(9)-0.118 9(9)-0.113 5(10)- 0.059 2(9)0.065 2(6)0.1 10 2(8)0.1 30 2(9)0.101 9(10)0.091(1)0.022( 1)0.13q1)0.1 18(3)0.32 1 (1)0.252( 1)0.396(1)0.305( 1)0.573( 1)0.542(2)0.575(2)0.626(2)0.520(1) 0.355 7(9) 0.075 3(9)Table 5. Non-hydrogen atom co-ordinates for [(TIMe,)3(Et,terpy)2(N0,)3]Y z X0.3 7q4)0.465(3)0-540(3)0.768(2)0.698( 3)0.7 18(4)0.799(4)0.801(6)0.829(9)0.864(3)0.850(3)Y0.141(6)0.1 12(3)0.12 l(2)0.132(2)0.123(2)0.123(3)0.125( 3)0.1 12(6)0.152(7)0.133( 3)0.128( 3)z0.108(2)0.042 q 12)0.023 5( 13)0.066 4(6)0.084 O( 10)0.1 14 q10)0.125 8(11)0.162 O(18)0.172 9(20)0.105 3(13)0.075 9( 10)0.754 89(9)10.782(2)0.747(2)1.040(2)0.152 19(9)0.029(3)0.285(2)0.13 l(2)1 140.009 22(3)-0.042 Ol(4)0.01 1 2(7)- 0.042 3( 7)-0.001 l(7)0.614(2)0.54 1 (4)0.465(3)0.461(3)0.373(4)0.383(3)0.535(3)0.603(3)0.612(2)0.6 19( 3)0.547( 3)0.467( 3)0.392(4)0.139(2)0.124(2)0.1 18(2)0.123(2)0.1 17(4)0.13 l(4)0.132(3)0.138( 3)0.123(1)0.124(2)0.1 17(3)0.109(3)0.085(4)-0.021 q9)-0.006 9(10)- 0.022 q 10)-0.051 9(13)-0.067 l(9)-0.095 l(15)-0.068 5( 10)-0.05 1 9(9)0.039 O(8)0.068 6( 12)0.086 4(9)0.073 2( 12)0.093(2)0.8 3 3( 2)0.900(2)0.827(2)0.771(2)I0.945(2)10.196(2)0.206(2)0.201 (2)0.183( 2)0.203(2)1 14114-0.075( 1)- 0.088 6(5)-0.049 5(6)- 0.092 q 7 )0.027(2)0.014 8(5)0.052( 1)nitrate group in the terpy complex (0.06 A).The thallium atomslie close to the rojected planes of the pyridyl rings (deviations(-0.74 A) and ring b of the terpy complex (1.07 A). Thedihedral angles between the pyridyl rings of Et,terpy are small,3.1 ” for rings a, b and 2.5” for rings b, c, and are similar to thoseobserved for other terpy complexes, e.g.2.4 and 4.9” for[Co(terpy)Cl, ].Ig However, consistent with the large deviationof TI from the plane of ring b of the terpy complex, much largerof 0.00--0.27 R ), except for ring a of the (py),CH2 complexdihedral angles are observed between the rings of terpy, 17.2 and18.0”, similar to those observed for [HgMe(Et,terpy)]NO,(15.4 and 18.6”) where the mercury atom also shows largedeviations from the pyridyl mean planes (0.886, 0.121, and1.032 A).’The weakly co-ordinating atoms in the equatorial regionaround PlMe, J + are approximately coplanar for the by),-CH, complex, where the atom deviations from the mean planefor ‘TlN,O,’ are + 0.01 to - 0.18 A; similarly, for the ‘TIN,O2944 J. CHEM. SOC. DALTON TRANS. 1986T a b 6. Thallium environments in the complexes. Entries in the first column, r, are the thallium-ligand distances (A); other entries in the matrix arethe angles (”) subtended at TI by the relevant atoms at the head of the row and columnr C(B) N(a1) N(b1) 0(1) 0(2) 0(2')2.139(13) 171.7(5) 90.3(4) 91.7(4) 87.9(4) 86.7(4) 86.4(5)2.108(13) 95.1(4) 95.9(4) 90.0(4) 86.2(4) 88.3(4)2.666(9) 72.5(3) 153.3(3) 162.0(3) 80.1(3)2.658(9) 81.0(3) 125.3(3) 152.5(3)2.770(9) 44.3(3) 126.3(3)2.915( 10) 82.0(3)2.847( 12)Deviations (A) of atoms from the ‘TIN,O,’ mean plane: TI,0.01; N(al), -0.06, N(bl), -0.07; 0(1), -0.09,0(2), -0.W; 0(2’), -0.18.For the nitrategroup: N-0(1,2,3) are 1.23(1), 1.27(1), and 1.22(1) A, with the angles opposite 0(1,2,3) being 120(1), 121(1), and 119(1)O; T1-0(1,2)-N, are 102.2(7)and 94.0(7)”; TI-0(2)-T1’ is 98.0(3) and N-O(2)-TI’ 165.8(8)”.For the (PY)~CH, group: TI-N(al)-C(2,6) are 115.4(7) and 123.9(7)”; TLN(bl)-C(2,6)are 116.2(7) and 125.2(7)”; and TI is 0.74 and 0.14 A from the mean planes of rings a and b, respectively. The prime refers to atoms related throughthe centre of symmetry ( - x , -y, 1 - 2).r C(B) O(4) O(1) N(a1) N(b1) N(c1)2.13 1 (1 5 ) 169.6(6) 88.2(5) 74.5(5) 93.6(5) 87.7( 5 ) 95.2(5)2.1 16(14) 83.6(5) 97.6(5) 91.9(4) 102.6(4) 89.1(5)2.932( 12) 78.5(4) 83.9(3) 146.3(3) 152.3(3)3.250( 19) 158.9(4) 131.9(4) 76.q4)2.620(10) 63.0(3) 123.1(3)2.650(9) 61.3(3)2.63 1 (10)Deviations (A) of atoms from the ‘TIN302’ mean plane: TI, 0.00; N(a1) -0.07; N(bl), 0.23; N(cl), -0.21; O( I), 0.73; 0(4), 0.00.For the nitrate group:N-0(1,2,3) are 1.15(3), 1.13(3), and 1.09(2) A; with the angles opposite 0(1,2,3) being 120(2), 107(2), and 132(2)”;TLO(l)-N is lSl(1)O. For the terpygroup: TI-N(aI)-C(2,6) are 120.0(8) and 119.8(8)”; TLN(bl)-C(2,6) 120.1(7) and 114.8(7)”; Tl-N(cl)-C(2,6) 121.1(8) and 121.2(8)”; and TI is 0.09,1.07, and 0.03 A from the mean planes of rings a, b, and c.r C(1B) O(12) O(21) N(a1) N(b1) N(c1)2.04(4) 166(1) 88(l) 94(1) 89(1) 97( 1) 95( 1)2.09(4) 79(1) 78(1) 93(1) 96(1) 95( 1)3.1 l(3) 151(1) 145(1) 83( 1)2.66( 3) 63( 1)2.99(3) 7q1) 83(1) 145(1) 152(1)2.62(3) 63(1) 126(1)2.61 (3)Deviations (A) of atoms from the ‘TlN,O,’ mean plane: TI, 0.00; N(aI), -0.09, N(bl), 0.25; N(cl), 0.02; 0(12), 0.10; 0(21), 0.13.For the Et,terpygroup: TI-N(aI)-C(2,6) are 118(3) and 129(3)”; TI-N(bl)-C(2,6) 116(2) and 117(3)”; TI--N(cI)-C(2,6) 121(3) and 113(3)”; and TI is 0.00,0.24, and0.27 A from the mean planes of rings a, b, and c.(ii) Tl(2); primed atoms are generated by the two-fold rotorAtom r O(11) O(12) O(21)C(2A) 1.97(4) 87(1) 93(1) 82(1)O( 11) 2.72(2) 44(1) 118(1)O( 12) 2.85(3) 75( 1)O(21) 2.81(2)Deviations (A) of atoms from the ‘TIO,’ mean planes: TI, 0.00; 0(12,12’), 0.26, -0.26 O(11,l l’), -0.08,0.08; 0(21,21’), -0.38,0.38. For the nitrategroups: N(l)-O(11--13)are 1.22(5), 1.17(5),and 1.26(5)A;N(2)-0(21,22)are 1.27(5)and 1.09(9)A; with theanglesO(11--13)at N(1) 123(4), 113(4),and 124(4)”, and the angles opposite 0(21,22) at N(2) 117(4) and 127(4)”; ll(2)-0(11,12)-N(1) are 98(2) and 93(3)”; Tl(l)-O(l2)-N(l), Tl(2) are154(3) and 109(1)”; T1(2)-0(21)-N(2) is 93(4)”; and T1(1)-0(21)-N(2), Tl(2) are 147(3) and 107(1)”.group in the Et,terpy complex, deviations of +0.25 to -0.09 Aoccur (Table 6).The ‘TIN,O,’ mean plane of the terpy complexhas atom deviations of +0.23 to -0.21 A, except for the moredistant nitrate oxygen, O(l)[TI 0 3.25(2) A, +0.73 A frommean plane]. For the ‘T10,‘ mean plane in the Et,terpycomplex, atoms 0(12), 0(11’), and O(21’) occur 0.26,0.08, and0.38 A from the plane, with the corresponding atoms related bythe two-fold axis on the opposite side of the plane, so thatalternate oxygens occur above and below the plane.The work reported here indicates that nitrogen-donor ligandsbind to dimethylthallium(rrr) in methanol, and for the threecomplexes whose structures have been determined crystallo-graphically the C-Tl-C groups are slightly bent away from thenitrogen-donor ligands which bind more strongly than thJ.CHEM. SOC. DALTON TRANS. 1986 945nitrate groups. Complex co-ordination geometries occur,involving weakly bridging nitrate groups in two complexes,with thallium geometries characterised by strong thallium-carbon bonding, and the presence of weak TI -. . N and/orT1 0 interactions in approximate equatorial planes to give‘TIC,N , O,’, ‘TIC, N , 0 ,,* and ‘TIC, 06.*ExperimentalDimethylthallium(rrr) iodide and nitrate,20*2’ 4,4’-diethyl-2,2’-bipyridyl (Et , bipy),, N-methyl-2-(pyridin-2-yl)imidazole(~ymim),~ bis(pyridin-2-y1)methane [(py)2CH2],23 bis(N-methylimidazol-2-y1)methanol [(mim),CHOH],24 4,4’,4’’-tri-ethyl-2,2’:6’,2”-terpyridyl (Et,ter~y),,~ and 2-(pyridin-2-yl)-imidazole26 were prepared as described. The remaining ligandswere obtained commercially, and were used as received. Protonspectra were measured at 300 MHz with a Bruker AM-300instrument, i.r. spectra of complexes as Nujol and hexachloro-butadiene mulls between KBr plates with a Hitachi 270-30spectrophotometer.Molecular weights were measured with aKriauer vapour-pressure osmometer. Microanalyses were bythe Australian Microanalytical Service, Melbourne.Syntheses.-Nitrate complexes. These complexes were ob-tained as colourless crystals in 28-37% yield. In a typicalsynthesis, dimethylthallium(r1r) nitrate (0.304 g, 1.03 mmol) wasadded to 4,4’-diethyl-2,2’-bipyridyl (0.193 g, 0.909 mmol) inacetone (30 cm3) and the suspension stirred for 4 h.Thesuspension was filtered to remove a small quantity ofundissolved dimethylthallium(rr~) nitrate, and the colourlessfiltrate allowed to evaporate slowly. At low volume, crystals of[TlMe,(Et,bipy)]NO, were collected, washed with coldacetone, and dried under vacuum over P205 (0.13 g, 28%).[TlMe,L] (L = pyim or pybzim). The silver(1) complexesAg(pyim) and Ag(pybzim) were obtained using the methoddescribed for related complexes of silver(^),^' involving additionof a solution of silver(1) nitrate in concentrated NH,(aq) tosolutions of py-Him and py-Hbzim in ethanol.The cream-coloured precipitates were collected, washed with ethanol, anddried under vacuum over P205. In a typical preparation, amixture of dimethylthallium(rrr) iodide (0.867 g, 2.40 mmol) andAg(pyim) (0.597 g, 2.37 mmol) in dry, distilled, dichloromethane(30 cm3) was refluxed under nitrogen until yellow silver(1)iodide was observed, and then refluxed for 1 h. On cooling, AgIwas removed by filtration through Celite under nitrogen, andthe filtrate reduced to low volume by rotary evaporation. Theremaining solvent was removed on a vacuum line, giving a palepink solid, [TIMe,(pyim)] (0.683 g, 76%). The complex[TlMe,(pybzim)] is pale yellow.[(TlMe,),L] (L = biim or bibzim). In a typical synthesis,dimethylthallium(rrr) iodide (1.489 g, 4.12 mmol) was added toan almost boiling, filtered, solution obtained by addition ofsodium hydroxide (ca.1 g) to 2,2’-bi-imidazole (0.323 g, 2.41mmol) in water (30 cm3). The light brown precipitate formedwas collected, washed with water, and dried under vacuum overP205. The crude complex was recrystallised by dissolution inacetone (30 cm3), filtration to remove a small quantity ofinsoluble residue, and evaporation to low volume. Yellow-brown crystals of [(TlMe,), biim] were collected, washed withcold acetone (ca. 1 cm3), and dried under vacuum over P205(1.014 g, 70%). Crude [(TlMe,),bibzim] was recrystallised fromchloroform, following a similar procedure (57%).Crystallography.-Unique data sets were measured to thespecified 28,,,, limit at 295 K using a Syntex PT four-circlediffractometer fitted with a monochromatic Mo-K, radiationsource, and operating in conventional 28-0 scan mode.N Independent reflections were obtained, No with I > 3a(I)being considered ‘observed’ and used in the basically 9 x 9block-diagonal least-squares refinement after analyticalabsorption correction, and solution of the structure by theheavy-atom method. Anisotropic thermal parameters wererefined for the non-hydrogen atoms; estimated values of x,y,z,and Uis0 for hydrogen atoms were included.Residuals R,R’(statistical weights) at convergence are quoted on IFI. Neutralcomplex scattering factors were used;28 computation used theXTAL 83 program system,’ implemented by S. R. Hall on aPerkin-Elmer 3240 computer.Key results and atom numberingare given in the Figure and Tables 2-6.AcknowledgementsThis work was supported by the University of Tasmania and theAustralian Research Grants Scheme.References1 T. L. Blundell and H. M. Powell, Chem. Commun., 1967,54.2 K. Henrick, R. W. Matthews, B. L. Podejma, and P. A. Tasker, J.Chem. SOC., Chem. Commun., 1982,118.3 J. Crowder, K. Henrick, R. W. Matthews, and B. L. Podejma, J.Chem. Res., 1983, (S), 82.4 D. L. Hughes and M. R. Truter, J. Chem. SOC., Chem. Commun., 1982,727.5 A. J. Canty, N. Chaichit, B. M. Gatehouse, E. E. George, and G.Hayhurst, Inorg. Chem., 1981,20,2414.6 G . B. Deacon, J. M. Patrick, B. W. Skelton, N. C. Thomas, and A. H.White, Aust. J. Chem., 1984,37,929.7 M. C. Ganorkar and M.H. B. Stiddard, J. Chem. SOC., 1965, 5346;G. B. Deacon and J. C. Parrott, Aust. J. Chem., 1974,27,2547; C. C.Addison, R. Davis, and N. Logan, J. Chem. Soc., Dalton Trans., 1974,2070; A. L. Crumbliss and A. T. Poulos, Inorg. Chem., 1975,14, 1529;D. M. W. Buck and P. Moore, J. Chem. Soc., Dalton Trans., 1976,638.8 1. R. Beattie and P. A. Cocking, J. Chem. SOC., 1965,3860.9 J. R. Cook and D. F. Martin, J. Inorg. Nucl. Chem., 1964,26, 1249.10 Y. Kawasaki and R. Kitano, Chem. Lett., 1978,1427.11 Y. Kawasaki and N. Okuda, Chem. Lett., 1982,1161.12 I. C. Calder, T. McL. Spotswood, and C. I. Tanzer, Aust. J. Chem.,1967.20, 1195; T. McL. Spotswood and C. I. Tanzer, ibid., pp. 1213,1227.13 S. Castellano, H. Gunther, and S. Ebersole, J. Phys. Chem., 1965,69,4 1 66.14 A. J. Canty and A. Marker, Inorg. Chem., 1976,15,425.15 E. Bielli, P. M. Gidney, R. D. Gillard, and B. T. Heaton, J. Chem.16 B. Walther, A. Zschunke, B. Adler, A. Kolbe, and S. Bauer, 2. Anorg.17 L. Pauling, ‘The Nature of the Chemical Bond,’ 3rd edn., Cornell18 A. Bondi, J. Phys. Chem., 1964,68,441.19 E. Goldschmied and N. C. Stephenson, Acra Crystaflogr., Sect. B,20 H. Gilman and R. G. Jones, J. Am. Chem. SOC., 1950,72, 1760.21 A. E. Goddard, J. Chem. SOC., 1921, 672.22 G. M. Badger and W. H. F. Sasse, J. Chem. SOC., 1956, 616.23 E. Leete and L. Marion, Can. J. Chem., 1952, 30, 563.24 A. J. Canty, E. E. George, and C. V. Lee, Aust. J. Chem., 1983,36,415.25 P. E. Rosevear and W. H. F. Sasse, J. Heterocycf. Chem., 1971,8,483.26 B. Chiswell, F. Lions, and B. S. Morris, Inorg. Chem., 1964, 3, 110.27 E. Buchner and M. Fritsch, Chem. Ber., 1893, 26, 256.28 J. A. Ibers and W. C. Hamilton (eds.), ‘International Tables for X-Ray Crystallography,’ Kynoch Press, Birmingham, 1974, vol. 4.29 J. M. Stewart and S. R. Hall (eds.), The XTAL System, TechnicalReport TR- 1364, Computer Science Center, University of Maryland,1983.SOC., Dalton Trans., 1974,2133.Alfg. Chem., 1976,427, 137.University Press, Ithaca, New York, 1960, p. 260.1970, 26, 1867.Received 25th June 1985; Paper 5/105