4623
Inorg. Chem. 1989, 28,4623-4629
Contribution from the Laboratory for Molecular Structure and Bonding, Department of Chemistry, Texas A&M University, College Station, Texas 77843
Luminescent Extended One-Dimensional Heterobimetallic Chain Compounds with Relativistic Metal-Metal Bonds. Synthesis, Crystal Structures, and Spectroscopic P ) ~ = [CH2P(S)Ph2T) Studies of AuTI(MTP)~and A U ~ P ~ ( M T(MTP Suning Wang, Guillermo Garzbn, Christopher King, Ju-Chun Wang, and John P. Fackler, Jr.* Received July 25, 1989
The heterobimetallic complexes AuT1(CH2P(S)Ph2)2(2) and A U ~ P ~ ( C H ~ P ( S(3)) Pwere ~ ~ obtained )~ in good yields from the (1) with TI2SO4and Pb(N03)2,respectively. ,Their structures were determined by sinreactions of PPN[AU(CH~P(S)P~~)~] gle-crystal X-ray diffraction. Compounds 2 and 3 form extended one-dimensional linear chain polymers with short metal-metal separations (-3.0 A) in the solid state. 2 crystallizes in the P2,/a space group with unit cell dimensions a = 24.368 (4) A, b = 11.655 (2) A, c = 9.445 (2) A, 0 = 101.13 (2)", V = 2632.2 (8) A', and Z = 4, while 3 crystallizes in the I2/a (C2/c space and group with unit cell dimensions a = 22.476 ( 5 ) A, b = 9.008 (2) A, c = 31.476 (8) A, fi = 107.19 (2), V = 6088 (2) Z = 4. Both of 2 and 3 are strongly luminescent when irradiated with UV light. The solid of 2 emits at 575 nm (298 K) with a lifetime of 0.98 ws, while the solid of 3 emits at 752 nm (298 K) with a lifetime of 22 ns. Luminescence is attributed to interactions between metal atoms in these compounds. Studies of the solid of 3 by'scanning electron microscopy (SEM) indicate that fibers of 3 are either conducting or semiconducting.
13,
Introduction Extended linear chain compounds have attracted the attention of chemists and physicists for many years because of their fascinating and unique chemical and physical prmperties.'z Although numerous extended chain compounds have been reported, the syntheses of these compounds and the rationalization of the bonding of one-dimensional chain structures still remain as a challenge to chemists and theorists. Among the known one-dimensional chain compounds, few are bimetallic. Some gold(1) dimers with sulfur-coordinated chelating ligands have been known to form one-dimensional chains in the solid state with various Au(I)-.Au(I) separations (2.76-3.40 A).3 However, heterobimetallic analogues were previously unknown. The synthesis and characterization of heterobimetallic linear chain compounds, 11, have thus become of special interest to us. Upon reaction of PPN[Au(MTP)2] (PPN = [(PhsP)2N]+; MTP = [CH2P(S)PhJ) with appropriate metal ions, Au,Pt(MTP),, Au2Pb(MTP)4,and AuTl(MTP), have been prepared. Each is a one-dimensional chain in the solid state. The structure of Au2Pt(MTP), was reported earlier., The structure of AuTl(MTP), has been described in an preliminary comm~nication.~ The compounds Au2Pb(MTP), and AuTl(MTP), not only have unique one-dimensional structures but also show very interesting properties of luminescence. Although a variety of luminescent organometallic complexes have been reported: most are metal carbonyl complexes or binuclear or polynuclear transition-metal complexes with at least one metal atom in a d8 electronic conf i g ~ r a t i o n . ~Very , ~ little is known about luminescent binuclear or polynuclear metal complexes with d'O and s2 electronic configurations. Recently Gray et al. have described the luminescence of binuclear palladium and platinum complexes with dlo-dIo configuration." We have also discovered that a number of gold(1) dimers are luminescent.8b We report here the syntheses and characterization of AuTl(MTP), and Au2Pb(MTP)4 and the spectroscopic study of their fascinating luminescence, the first extended linear chain heterobinuclear and heterotrinuclear species showing such behavior.8c Results and Discussion Synthesis and Characterization of AuTI(MTP), (2) and Au2Pb(MTP), (3). The reagent PPN[Au(MTP),] (1) has been found to be very useful for the synthesis of heterobimetallic complexes. 1 reacts readily with M+ or M2+ cations to generate the corresponding neutral bimetallic species. The yellow crystalline compound AuTI(MTP)~(2) was obtained in 64% yield by the addition of a methanol solution of T12S04to the CH2C12solution of 1 in a 1:l ratio of Au:Tl. Addition of a solution of Pb(N03), To whom correspondence should be addressed.
0020-1669/89/1328-4623$01.50/0
in methanol to a CH2Clzsolution of 1 in a 1:2 ratio resulted in the formation of the bronze-colored crystalline Au2Pb(MTP), (3) in 12%yield. The 'H spectra show the methylene doublet of the MTP ligand in 2 and 3 is shifted downfield ( 8 = 1.64 ppm, .IPH= 12 Hz, in CDC13,for 2; 6 = 1.71 ppm, .IPH= 12 Hz, in CDC13, for 3) from that of 1 (6 = 1.52 ppm, .IPH= 15 Hz, in CDC13). These shifts are independent of concentration, indicating the presence of a bonding interaction of the Tl(1) ion or Pb(I1) ion with the Au(MTP)2- anion. The 'H N M R spectra of 2 and 3 show no coupling of -CH2groups with TI (,05Tl, I = natural abundance 70%) or Pb (,07Pb, I = I/,, natural abundance 23%), an indication that the bonding of the TI+ ion or PbZ+ion with the Au(MTP),anion is through the sulfur atoms of Au(MTP)~-. The presence of bonding interactions of Pb2+ with Au(MTP); in solution is also supported by the 31PN M R spectrum of Au,Pb(MTP),, showing a singlet at 50.5 ppm with two 31P-207Pbcoupling satellites, JP-Pb= 16 Hz. A similar coupling was not observed for AuTl(MTP)2, probably due to the small coupling constant of 31P with 20sTl. Both compounds 2 and 3 were studied by scanning electron microscopy (SEM). Without a conductive coating, crystals of 2 did not yield a clear image due to the charging effects. In contrast, the bronze-colored (solvent free) crystals of 3 gave a very sharp SEM image, indicating that the compound 3 is conducting or semicond~cting.~SEM photographs show that the solid of 3 has a one-dimensional fiberlike morphology (Figure 1 ) . The powder reflectance spectrum of 3 (Figure 2) shows a broad band in the visible region with a cutoff at ca. 600 nm, suggesting the Miller, J. S., Ed. Extended Linear Chain Compounds; Plenum: New York and London, 1981-1983; Vol. 1-3. Hoffmann, R. Angew. Chem., Ini. Ed. Engl. 1987, 26, 846. (a) Mazany, A. A.; Fackler, J. P:, Jr. J . Am. Chem. SOC.1984, 106, 801. (b) Mazany, A. A. Ph.D. Thesis, Case Western Reserve University, 1984. (c) Jones, P. G. GoldEull. 1981, 14, 102. Murray, H. H.; Briggs, D. A,; Garzon, G.; Raptis, R. G.; Porter, L. C.; Fackler, J. P., Jr. Organometallics 1987, 6, 1992. Wang, S.; Fackler, J. P., Jr.; King, C.; Wang, J. C. J . Am. Chem. SOC. 1988, 110, 3308-3310. (a) Lees, A. J. Chem. Rev.1987,87,71 1. (b) Ferraudi, G. J. Elements of Inorganic Photochemistry; John wiley & Sons: New York, 1988. (a) King, C.; Auerbach, R. A.; Fronczek, F. R.; Roundhill, D. M. J . Am. Chem. SOC.1986, 108, 5626. (b) Fordyce, W. A,; Brummer, J. G.; Crosby, G. A. J . Am. Chem. SOC.1981,103,7061. (c) Mann, K. R.; Lewis, N. S.; Williams, R.M.; Gray, H. B.; Gordon, J. C., 11. Inorg. Chem. 1978.17, 828. (d) Balch, A. L.; Nagle, J. K.; Olmstead, M. M.; Reedy, P. E., Jr. J . Am. Chem. SOC.1987, 109, 4123. (a) Harvey, P. D.; Gray, H. B. J. Am. Chem. SOC.1988,110,2145. (b) King, C.; Wang, J. C.; Khan, Md. N. I.; Fackler, J. P. Jr. Inorg. Chem. 1989, 28, 2145-2149. (c) See also: Balch, A. L.; Davies, B. J.; Olmstead, M. M. Inorg. Chem. 1989, 28, 3148. Goldstein, J. I., et al., Eds. Scanning Electron Microscopy and X-Ray Microanalysis; Plenum Press: New York and London, 1981.
0 1989 American Chemical Society
4624 Inorganic Chemistry. Vol. 28, No. 26, 1989
Wang et al. Table 11. Atomic Coordinates (XIO‘) and Isotropic Thermal ~
%
with conducting film
4w
600
500 Vavelengthlnm
Figure 2. Powder reflectance spctrum of 3. Table 1. Crystallographic Data for AUTI(MTP)~(2)
(3) .. formula
C26H2,TIAuS2P2 863.4 W a 24.368 (4) 11.655 (2) 9.445 (2) 101.13 (2) 2632.2 (8) A
scan method
w
28 range. deg 2-45 no. of reflens mead 3950 no. of reflcns for F: t 30(F.*) 1659 no. of paramn refined 111 transm factor: m u . min 1 .00, 0.44 F 0.0625 0.0647 R.k gaadncss-of-fit indicatof 1.341 largest shiftlesd (finalcycle) 0.W3 largest peak. =/A3 3.44
~
atom Au
and Au2Pb(MTP), CI2HIIPbAu2S,P,. 2C.H.O 1670.5
.~
76:!; (6) 9.008 (2) 31.476 (8) 107.19 (2) 6088 (2)
*
w
245 4443 1524 137 0.79, 0.72 0.0351 0.0405 1.356 0.W 0.78
presence of nondiscrete levels in the ground and/or excited state(s). Both 2 and 3 glow with a distinctive colored luminescence in the solid state when irradiated by a UV lamp. 2 strongly emits a yellow-orange color, while 3 emits a red color in the solid state and a yellow color in solution. In order to understand these unusual phenomena, single-crystal X-ray diffraction structural analysis and excitation and emission spectroscopic studies were performed. Theoretical calculations using the Fenske-Hall method were carried out for both compounds.
~
(d2~ x tnsr ~
rnr ~ rt
.
.
~
X
Y
z
2450 (1) 2369 i i i 3706 (4) 1439 (4) 3425 (4) 1680 (6) 3299 (IO) 1588 (IO) 41 I5 (8) 4126 (8) 3782 (8) 3427 (8) 3416 (8) 3760 (8) 4617 (IO) 5171 (IO) 5524 (IO) 5324 (IO) 4770 (IO) 4417 (IO) 1937 (11) 2123 (11) 2069 ( I 1) 1830(11) 1644(11) 1698 (11) 389 (13) -193 (13) 4 8 4 (1 3) -193 (13) 389 (13) 680 (13)
2980 11) 449 ( i j 2357 (7) 2445 (8) 1008 (9) 882 (IO) 2781 (22) 3163 (22) 4486 (19) 5464 (19) 5532 (19) 4623 (19) 3645 (19) 3577 (19) 2460 (22) 2242 (22) 1669 (22) 1314 (22) 1532 (22) 2105 (22) 2867 (1 6) 3566 (16) 4755 (16) 5245 (16) 4546 (16) 3357 (16) 1495 (22) 1502 (22) 2539 (22) 3569 (22) 3562 (22) 2525 (22)
5425 12) 5273 (2) 5256 (IO) 2650 (12) 4111 (13) 2442 (15) 6627 (28) 4480 (28) 4623 (21) 3777 (21) 2416 (21) 1901 (21) 2747 (21) 4108 (21) 7560 (27) 8215 (27) 7453 (27) 6037 (27) 5383 (27) 6144 (27) 312 (29) -699 (29) 4 2 6 (29) 459 (29) 1469 (29) 1396 (29) 1800 (33) 1403 (33) 1303 (33) 1600 (33) 1997 (33) 2097 (33)
38 (3). 53 (4). 67 (5)’ 93 (6)’ 16 (6) 19 (6) 51 (9) 65 (11) 68 (11) 57 (IO) 62 (11) 35 (8) 82 (13) 115 (18) 87 (14) 86 (14) 82 (13) 46 (9) 74 (12) 91 (IS) 84 (13) 107 (16) 81 (13) 57 (IO) 98 (16) 142 (22) 110 (17) 104 (17) 89 (15) 69 (12)
‘Estimated standard deviations in the least significant digits arc given in parentheses. ’For values with asterisks, the quivalcnt isctropic U 15 defined as onc-third of the trace of the U,, tensor. Table Ill. Bond Leneths 1Al and Angles (deg) for 2‘
P(2)
