Inorg. Chem. 1981, 20, 572-578
512
Contribution from the Department of Chemistry, Texas A&M University, College Station, Texas 77843
Tetrakis( 2-amino-4-methylbenzothiazolato)dimolybdenumTetrahydrofuranate, (acetato)dimolybdenum Bis( tetrahydrofuranate), Tris(2-amino-4-methylbenzothiazolato) and Tetrakis(2-amino-4-chlorobenzothiazolato)dimolybdenumBis(tetrahydr0furanate). Quadruply Bonded Compounds with Bridging Ligands Derived from a Five-Membered Ring System F. ALBERT COTTON* and WILLIAM H. ILSLEY Received June 9, 1980
The structures of Mq(ambt)3(CH3C0J.2THF (l),M ~ ( a m b t ) ~ - m (2)F (ambt = the anion of 2-am.ino4methylbenzothiazde, obtained by removal of one amine hydrogen atom), and Mo2(acbt),.2THF (3) (acbt = the anion of 2-amino-4-chlorobenzothiazole, obtained by removal of one amine hydrogen atom) are reported. These are the first examples of compounds in which the ligand bridge system is derived from a five-membered heterocyclic ring system. Compound 1 crystallizes in the monoclinic space group R 1 / nwith unit cell parameters a = 10.934 (3) A, b = 25.005 (7) A, c = 13.648 (2) A, fi = 92.74 (2)O, V = 3727 (3) A), and Z = 4. Each molecule resides on a eneral position, and the THF molecules occupy the voids between the molecules. The Mo-Mo bond length is 2.093 (3) ,and the rotational conformation is essentially eclipsed. Compound 2 crystallizes in the monoclinic space group R , / c with unit cell parameters a = 13.201 (2) A, b = 10.967 (2) A, c = 14.075 (2) A, j3 = 115.33 (3)O, V = 1842 (1) AS,and Z = 2. Each molecule as well as each of the THF molecules resides on a center of inversion of the unit cell, the latter being, therefore, disordered. The ligands are arranged so as to give idealized Ca symmetry, but there are inequalities in the N-Mo-N angles in response to methyl-methyl repulsions. The Mo-Mo bond length is 2.103 (1) A. Compound 3 crystallizes in the triclinic space group Pi with unit cell parameters a = 10.422 (2) A, b = 12.041 (2) A, c = 10.129 (1) A, a = 97.63 (l)', @ = 118.47 (l)', y = 66.88 (I)', V = 1025.3 (4) A), and Z = 1. Each molecule resides on a center of inversion of the unit cell, and the THF molecules occupy the voids between the molecules. As in 2, the ligands are arranged so as to give idealized C2, symmetry, but this is again reduced to only inversion symmetry by angle changes in response to repulsions between the chlorine atoms. The Mo-Mo bond length is 2.1 17 (1) A. Each compound shows two distinctly different Mo-N distances of -2.14 and 2.21 A, which can be accounted for by steric repulsions between the methyl groups of the ambt or chlorine atoms of the acbt ligands. Distances in compound 1 also suggest that there may be a trans effect in this molecule since the M A distances of -2.15 A are significantly larger than those previously observed, i.e., 2.10-2.1 1 A.
R
Introduction Since the characterization of the quadruple bond, in [Re2C1812-, in 1964, a wide range of quadruply bound bimetallic compounds has been prepared and characterized crystallographically.' The most extensively studied have been the dimolybdenum species since they are in general the easiest to prepare and handle. Among the vast number of such compounds that have been studied,2 the majority have been derived from the ligand types \x-x/
Or
x'
JQ
X=N,O Y=C,N,O
where the bridge is part of an alkyl system or derived from a six-membered ring system. There have been no examples in which the bridge system is derived from a five-membered ring system. Although a number of attempts have been made in this laboratory to prepare such complexes, the products have heretofore invariably been insoluble, though crystalline, materials. W e have now succeeded in obtaining soluble compounds, with ligands derived from 2-amino-4-methylbenzothiazole, Hambt, and 2-amino-4-chlorobenzothiazole, Hacbt. These molecules can be deprotonated to anions, by using butyllithium, as shown in eq 1. W e have prepared and characterized three compounds, MO~(~~~~)~(CH,CO ~ )M. ~ ~T( aHmFb t ) ~ e T(2), (l), H F and (1) Cotton, F. A. Acc. Chem. Res. 1978, 11, 225. (2) Bino, A,; Cotton, F. A. Proceedings of the 3rd International Conference on the Chemistry and Uses of Molybdenum, Ann Arbor, Mich., August, 1979.
0020-1669/81/1320-0572$01.00/0
Table 1. Crystallographic Parameters uarameter 1 2 3' space group P2, In P2,lc pi a, A 10.934 (3) 13.201 (2) 10.422 (2) b; A 25.005 (7j 10.967 (2) 12.041 i2j 13.648 (2) 14.075 (2) 10.129 (1) C, A 90.0 90.0 97.63 (1) (2, deg 92.14 (2) 115.33 (3) 118.47 (1) P, deg 90.0 90.0 66.88 (1) del3 Z 4 2 1 fw 884.81 1070.66 91 6.88 0.20 x 0.20 x 0.20 X 0.30 X 0.10 X 0.30 X cryst size, mm 0.20 0.25 0.25 p , cm-I 8.6 95 11.008 9.307 20 range, deg 045 045 045 no. data 3329 1794 2652 F,' > 30(F,') 1554 2262 1768 no. of variables 140 229 262 0.062 0.091 0.048 Rl 0.119 0.085 0.066 R2 1.710 2.103 2.230 ESD 1.653 1.734 d,(calcd), dcm' 1577 7 9
Mo2(acbt),.2THF (3), and we present here a detailed discussion of their structures.
Hambt, R = CH, Hacbt, R = CI
0 1981 American Chemical Society
J ambt-, R = CH, acbt-, R = Q
Inorganic Chemistry, Vol. 20, No. 2, 1981 513
Dimolybdenum 2-Aminobenzothiazolato Complexes
Table 11. Positional and Thermal Parameters and Their Estimated Standard Deviations for Mo,(ambt),(CH3C0,).2THF (1>" atom X z Y Bz 2 B33 Bl 3 BIZ 0.5322 (3) 0.3707 (1) 0.6884 (2) 4.2 (1) -0.2 (1) 4.8 (1) -0.5 (1) 0.4563 (2) 0.4464 (1) 4.4 (1) -0.4 (1) 4.5 (1) 0.3 (1) 0.6609 (2) 0.4732 (4) 0.6699 (9) 0.9579 (6) -0.7 (4) 9.5 (6) 3.8 (4) -2.0 (5) 0.8369 (8) 0.4620 (3) 05211 (7) 5.8 (5) 9.0 (5) 1.9 (4) -0.5 (4) 0.1455 (9) 0.3614 (4) 2.0 (4) 0.8237 (7) 7.0 (5) 10.1 (6) -3.6 (5) 0.3398 (7) 0.458 (2) -0.4 (9) 0551 (1) 3.5 (8) 0.7 (9) 4.6 (9) 0.4192 (8) 0.374 (2) 1.4 (9) 0524 (1) 1.2 (9) 7 (1) 5 (1) 0.3931 (9) 0.613 (2) 0.826 (1) 2.7 (9) 6 (1) -2 (1) 3 (1) 0.4791 (9) 0.535 (2) 0.796 (2) 5 (1) 3 (1) 5 (1) 1 (1) 0.3924 (8) 0.706 (2) 0.614 (1) -0.3 (9) 5 (1) 6 (1) 1 (1) 0.4765 (9) 0.607 (2) 0.579 (1) -0.7 (9) 6 (1) 4 (1) -0 (1) 0.3464 (9) 0.359 (2) 0.759 (1) 4 (1) -0 (1) 7 (1) -3 (1) 0.289 (2) 0.4321 (9) 0.729 (2) 7 (1) 7 (1) -2 (1) 0 (1) at om X Y Z B , A' at om X Y Z O(3) 0.275 (3) 0.188 (1) 0.434 (2) 12.4 (9) C(17) 0.860 (3) 0.318 (1) 0.634 (2) O(4) 0586 (3) - -0.003 (1) 0.290 (2) 15.4 (11) C(18) 0.769 (3) 0.280 (1) 0.675 (2) 0.371 (1) 0.501 (2) 0.385 (1) 0.761 (2) C(19) 0.276 (3) C(1) 0.394 (3) 5.3 (7) 0.327 (3) 0.297 (1) 0.809 (2) 0.351 (1) 0.399 (2) C(20) C(2) 0.338 (3) 5.5 (7) 0.300 (1) 0.843 (2) 0.443 (1) 0.849 (2) C(21) 0.211 (3) C(3) 0.600 (2) 4.6 (6) 0.832 (2) 0.254 (2) 0.890 (3) 0.543 (3) 0.531 (1) C(22) 0.152 (4) C(4) 5.2 (7) 0.209 (1) 0.898 (2) 0.923 (2) 0.610 (3) 0.534 (1) C(5) C(23) 0.231 (3) 6.6 (8) 0.868 (2) 0.586 (1) 0.969 (2) 0.341 (3) 0.201 (1) C(24) C(6) 0.626 (3) 8.1 (9) 0.826 (2) 0.628 (1) 0.930 (3) 0.397 (3) 0.249 (1) C(25) C(7) 0.573 (3) 8.3 (10) 0.628 (1) 0.845 (3) 0.245 (1) 0.788 (3) C(26) 0.523 (3) C(8) 0.504 (3) 8 5 (10) 0.159 (2) 0.468 (4) 0.791 (2) 0.482 (3) 0575 (1) C(9) C(27) 0.382 (5) 5.9 (7) 0.579 (4) 0.349 (5) 0.162 (2) 0.702 (2) 0.407 (3) 0574 (1) C(28) C(10) 7.8 (9) 0.600 (4) 0.441 (1) 0.211 (2) C(11) 0.704 (2) 0575 (2) C(29) 0.280 (6) 3.8 (6) 0.210 (2) 0.513 (4) 0.603 (2) C(30) 0.221 (5) 0.822 (2) 0.370 (1) C(12) 4.4 (6) 0.230 (5) 0.400 (1) 0.554 (2) 0.553 (6) -0.052 (3) C(31) C(13) 0.906 (2) 4.3 (6) 0.387 (1) 0.348 (8) 0.540 (2) C(32) 0.472 (10) -0.052 (5) C(14) 1.031 (3) 6.6 (8) 0.264 (4) 0.386 (5) -0.040 (2) 0.573 (2) 1.058 (3) 0.336 (1) C(33) C(15) 7.1 (8) C(16) 0.979 (3) 0.302 (1) 0.619 (2) 7.5 (9) C(34) 0.460 (7) 0.021 (3) 0.291 (5)
BZ3
0.6 (1) 0.4 (1) -0.6 (4) -0.5 (4) 0.3 (5) 0.7 (8) 0.3 (9) 2.3 (9) -0 (1) 0 (1) 0 (1)
-1 (1) 2 (1) B , A'
5.7 (7) 7 5 (9) 6.1 (8) 6.8 (8) 6.9 (8) 9.5 (11) 8.0 (9) 8.3 (10) 7.0 (8) 8.5 (10) 14.7 (17) 16.8 (19) 17.6 (21) 15.1 (17) 19.5 (23) 34.9 (48) 15.0 (17) 22.8 (28)
aTheformoftheanisotropicthermalparameterisexp[-~/4(B,,hZa*2 +B,,kZb*' +B331Zc*2+ 2BIzhka*b* + 2BI3hla*c* + 2Bz&klb*c*)l.
Table 111. Positional and Thermal Parameters and Their Estimated Standard Deviations for Mo. (ambt);THF (2)" atom X Y Z B,I B,, B3 3 Bl, 3.39 (3) 3.35 (3) 2.74 (2) -0.49 (4) 0.05850 (8) 0.05242 (6) 0.48609 (7) Mo(l) 4.3 (1) -0.2 (1) 6.2 (2) 0.2616 (2) 4.2 (1) -0.1251 (3) S(1) 0.8309 (2) 4.69 (9) -0.9 (1) 5.2 (1) 3.6 (1) 0.2834 (3) -0.0499 (2) S(2) 0.7242 (2) -0.4 (3) 3.1 (3) 3.6 (3) 4.1 (4) 0.1826 (6) 0.6389 (6) 0.0062 (8) N(1) 3.3 (3) -0.3 (3) 0.0724 (5) 3.1 (3) 3.9 (4) 0.6675 (6) -0.1345 (8) N(2) -0.4 (3) 3.4 (3) 4.0 (3) 3.9 (4) 0.2028 (7) 0.0295 (5) N(3) 0.5813 (6) -0.9 (3) 3.1 (2) -0.0969 (5) 3.5 (3) 3.6 (4) 0.6064 (6) 0.0812 (7) N(4) atom
X
0.028 (1) 0.7009 (7) 0.7437 (8) 0.8392 (8) 0.9288 (10) 0.9127 (10) 0.8186 (9) 0.7315 (9) 0.6210 (14) 0.6262 (8)
Y
0.617 (2) -0.0761 (9) -0.2247 (9) -0.2306 (10) -0.3169 (13) -0.3925 (13) -0.3969 (12) -0.3110 (11) -0.3295 (18) 0.1806 (10)
Z
0.447 (1) 0.1656 (7) 0.0783 (7) 0.1732 (8) 0.1925 (9) 0.1111 (9) 0.0188 (9) 0.0004 (9) -0.0950 (13) -0.0372 (7)
B,A2
7.2 (4) 3.4 (2) 3.5 (2) 4.2 (2) 5.8 (3) 5.9 (3) 5.3 (3) 5.1 (3) 9.9 (5) 3.6 (2)
atom
m of the anisotropic thermal parameter is exp[- . 1 / 4 ( B l l h 2 a *+z B,,k'b*'
Experimental Section Materials. 2-Amino-4-methylbenzothiazole, Hambt, 2-amino-4chlorobenzothiazole, Hacbt, and n-butyllithium were purchased from Aldrich Chemical Co., Inc. All other compounds and solvents were of reagent grade or tetter from commercial sources. All solvents were dried over Na/K alloy and deoxygenated prior to use. Reactions were performed under argon by using standard Schlenk techniques. Preparation of MO~(~I~~~)~(CH~CO~).ZTHF. The monoanion of 2-amino-4-methylbenzothiazole, Hambt, was prepared by reacting the ligand (0.328 g, 2.0 mmol) with 1.3 mL of 1.6 M hexane solution of n-butyllithium in 25 rnL of THF. Dimolybdenum tetraacetate
Y
X
0.6588 0.7279 0.7942 0.7828 0.7111 0.6463 0.5657 0.0543 -0.0595
(7) (7) (8) (8) (8) (8) (13) (11)
(12)
0.0900 (9) 0.1917 (9) 0.2118 (10) 0.1280 (10) 0.0313 (10) 0.0113 (10) -0.0941 (17) 0.4976 (15) 0.5879 (16)
Bl3
B, 3
1.74 (2) 0.7 (1) 3.00 (7) 1.1 (2) 1.6 (2) 2.4 (2) 2.0 (2)
-0.87 (3) 0.2 (1) -0.40 (9) -0.1 (3) -0.5 (3) -0.3 (3) -1.1 (3)
Z
-0.1659 (7) -0.1489 (7) -0.2031 (8) -0.2805 (7) -0.3032 (8) -0.2490 (8) -0.2815 (12) 0.4510 (11) 0.4689 (12)
B, A'
3.3 (2) 3.3 (2) 4.2 (2) 4.0 (2) 4.1 (2) 4.3 (2) 8.9 (4) 7.4 (4) 8.4 (4)
+ B331zc*2+ 2B1,hka*b* + 2B,,hla*c* + 2B2,klb*c*)].
(0.214 g, 0.5 mmol) was added and the reaction mixture stirred for approximately 1 h. The mixture was filtered to give a red solution. 2 mg) were obtained by slow diffusion of a layer Yellow crystals (a. of hexane into the THF solution. Preparation of Mo,(ambt),-THF. This compound was obtained in a manner analogous to that described above except that the reaction was allowed to proceed for 36 h before filtration and layering. About 3 mg of product was isolated. Preparation of Mo(acbt),.ZTHF. The monoanion of 2-amino-4chlorobenzothiazole, Hacbt, was prepared by reacting the ligand (0.368 g, 2.0 mmol) with 1.3 mL of a 1.6 M hexane solution of n-butyllithium in 25 mL of THF. Dimolybdenum tetraacetate (0.214 g, 0.5 mmol)
Cotton and Ilsley
514 Inorganic Chemistry, Vol. 20, No. 2, 1981 Table IV. Positional and Thermal Parameters and Their Estimated Standard Deviations of Moz(acbt),.2THF (3)‘ atom
X
Y
z
Mo(1)
0.59356 (5) 1.0010 (2) 0.2443 (2) 0.6771 (2) 0.7926 (2) 0.4876 (5) 0.7057 (5) 0.7396 (5) 0.5434 (5) 0.6127 (6) 0.8452 (6) 0.8519 (7) 0.9824 (7) 1.1163 (7) 1.1173 (7) 0.9822 (6) 0.6882 (6) 0.5210 (6) 0.6430 (7) 0.6365 (7) 0.5047 (8) 0.3810 (8) 0.3935 (7)
0.91418 (4) 0.7551 (2) 1.3764 (2) 1.0870 (2) 1.1433 (2) 1.1432 (4) 0.9605 (4) 0.9708 (5) 1.1623 (4) 1.0659 (5) 0.9070 (5) 0.9622 (6) 0.9232 (6) 0.8264 (6) 0.7716 (6) 0.8147 (5) 1.0816 (5) 1.2769 (6) 1.2836 (6) 1.3939 (6) 1.4968 (7) 1.4938 (7) 1.3821 (7)
0.03402 (5) 0.2509 (2) -0.1186 (3) 0.4913 (2) -0.1031 (2) 0.1896 (5) 0.2676 (5) -0.0118 (5) -0.0811 (5) 0.2972 (6) 0.3980 (6) 0.5321 (6) 0.6707 (7) 0.6787 (7) 0.5508 (7) 0.4101 (6) -0.0591 (6) -0.1229 (6) -0.1420 (7) -0.1815 (8) -0.2041 (9) -0.1848 (9) -0.1454 (8)
Q(1)
Cl(2) S(1) S(2) N(l) N(2) N(3) N(4) C(l) C(2) C(3) C(4) C(5) C(6) C(7) C(8) C(9) C(10) C(11) C(12) C(13) C(14) atom C(102) C(103)
X
Y
z
0.143 (1) 0.116 (2)
0.366 (1) 0.305 (2)
0.178 (1) 0.281 (2)
Bll
1.96 (1) 3.38 (5) 4.57 (5) 3.44 (5) 3.36 (4) 2.6 (2) 2.2 (1) 2.8 (1) 2.4 (1) 2.9 (2) 2.5 (2) 3.7 (2) 3.7 (2) 3.8 (2) 3.8 (2) 2% (2) 2.9 (2) 3.3 (2) 3.5 (2) 4.6 (2) 5.5 (2) 5.2 (3) 3.3 (2) B , A’ 9 5 (3) 17.5 (7)
B’,
B33
BIZ
2.63 (2) 4.26 (7) 4.24 (8) 4.31 (7) 4.46 (7) 3.2 (2) 3.1 (2) 3.4 (2) 1.8 (2) 3.9 (2) 3.0 (2) 3.9 (2) 4.0 (3) 3.5 (3) 3.9 (2) 3.0 (2) 2.2 (2) 3.9 (2) 4.4 (3) 4.5 (3) 5.2 (3) 3.9 (3) 4.7 (3) atom
2.21 (2) 3.79 (6) 15.3 (1) 2.51 (5) 4.15 (5) 2.8 (2) 2.3 (2) 3.0 (2) 3.2 (2) 2.6 (2) 2.8 (2) 2.7 (2) 2.7 (2) 3.6 (3) 3.3 (2) 2.7 (2) 2.4 (2) 3.1 (2) 3.3 (2) 5.2 (3) 7.8 (4) 8.2 (4) 7.0 (3)
-0.56 (1) -0.38 (5) -0.30 (5) -0.87 (5) -1.22 (4) -0.9 (1) -0.6 (1) -0.6 (1) -0.3 (1) -1.6 (2) -1.2 (1) -1.5 (2) -1.3 (2) -1.1 (2) -1.7 (2) -1.1 (2) -0.4 (1) -1.5 (2) -1.5 (2) -1.4 (2) -2.7 (2) -1.4 (2) -1.1 (2)
C104 C105 O(101)
Bl 3
BZ 3
0.80 (1) 1.62 (4) 5.77 (5) 1.15 (4) 2.10 (3) 0.7 (1) 0.7 (1) 1.4 (1) 1.0 (1) 1.2 (1) 0.7 (1) 1.3 (1) 0.3 (2) 0.6 (2) 0.8 (2) 0.8 (1) 1.1 (1) 1.3 (1) 1.2 (2) 2.1 (2) 3.0 (2) 3.0 (2) 2.6 (2)
0.11 (1) 0.05 (6) 1.93 (8) -0.34 (5) 0.53 (5) 0.0 (2) 0.1 (1) 0.4 (2) 0.8 (1) -0.5 (2) 0.2 (2) 0.0 (2) 0.4 (2) 0.6 (2) 0.6 (2) 0.0 (2) 0.2 (2) -0.1 (2) 0.5 (2) 1.3 (2) 0.9 (3) 1.3 (3) 0.9 (2)
X
Y
z
B , A’
0.199 (2) 0.322 (1) 0.2919 (7)
0.345 (2) 0.386 (1) 0.3702 (6)
0.435 (2) 0.429 (1) 0.2779 (7)
17.6 (7) 10.8 (4) 8.2 (2)
’The form of the anisotropic thermal parameter is eXp[-1/,(81 Ih’p*’ + B,,k’b*’ + B3,1’c*’ + 2Bl,hku*b* + 28, ,hla*c*
ca
CIC
Figure 1. ORTEP drawing of the M~~(arnbt)~(CH$O~) molecule (1). Ellipsoids of thermal motion, scaled to enclose 30% of the electron density, represent each atom.
il3
Figure 2. ORTEP drawing of the Mo2(ambt)4molecule (2). Ellipsoids of thermal motion, scaled to enclose 30% of the electron density, represent each atom.
t 2B13klb*c*)].
Table V. Bond Distances for M o , ( ~ ~ ~ ~ ) ~ ( O , C C H ~(1) ).~THF atoms dist, A atoms dist, A 1.88 (8) 2.093 (3) 1.48 (8) 2.16 (1) 1.77 (7) 2.11 (2) 1.39 (2) 2.26 (2) 2.25 (2) 1.33 (3) 1.45 (3) 2.15 (1) 1.28 (3) 2.16 (2) 1 5 8 (3) 2.17 (2) 1.41 (3) 2.12 (2) 1.81 (2) 1.38 (3) 1.71 (2) 1.44 (3) 1.74 (2) 1.30 (3) 1.77 (2) 1.36 (3) 1.79 (3) 1.53 (3) 1.71 (2) 1.44 (3) 1.23 (2) 1.39 (2) 1.25 (2) 1.42 (3) 1.44 (4) 1.43 (3) 1.36 (4) 1.38 (3) 1.52 (5) 1.38 (3) 1.40 (3) 1 5 0 (6) 1 5 1 (3) 1.30 (2) 1.37 (3) 1.34 (2) 1.44 (3) 1.39 (2) 1.47 (3) 1.33 (2) 1.44 (3) 1.40 (2) 1.58 (5) 1.30 (3) C(23)C(24) 1.48 (3) 1.48 (5) C(24)C(25) 1.49 (3) C(25)4(26) 1.34 (5) was added and the reaction mixture stirred for approximately 16 h. The reaction mixture was then filtered, and orange crystals (a. 3-4 mg) were obtained by slow diffusion of a layer of hexane into the THF solution. X-ray Crystallography. Crystals suitable for X-ray analysis were embedded in epoxy cement within a glass capillary and mounted on either a Syntex Pi or Enraf-Nonius CAD-4F automatic diffractometer. The procedures used for data collection as well as methods used in the solution and refinement of the structure were standard and have been described previously for both S y n t e ~ and ) ~ CAD-43bdata. (3) (a) Cotton, F.A,; Ilsley, W. H.; Kairn, W.Inorg. Chem. 1979,18, 3569. (b) Bino, A,; Cotton, F. A,; Fanwick, P. E. Inorg. Chem. 1979,18,3558.
Dimolybdenum 2-Aminobenzothiazolato Complexes
Inorganic Chemistry, Vol. 20, No. 2, 1981 575 Table VII. Bond Distances for Mo,(ambt),.THF (2) atoms
dist, A
atoms
dist, A
1.45 (1) 1.36 (1) 1.36 (1) 1.42 (1) 1.52 (2) 1.40 (1) 1.41 (1) 1.40 (1) 1.38 (1) 1.36 (1) 1.39 (1) 1.50 (2) 1.45 (2) 1.36 (2) 1.36 (2)
Figure 3. ORTEP drawing of the Mo,(acbt), molecule (2). Ellipsoids of thermal motion, scaled to enclose 30% of the electron density, represent each atom.
Table VI. Bond Angles for Mo2(ambt),(02CCH,).2THF (1)
93.0 (2) 92.8 (2) 93.2 (2) 93.4 (2) 173.0 (2) 85.8 (3) 90.2 (3) 90.0 (3) 93.2 (3) 172.5 (2) 89.6 (4) 89.1 (4) 117.6 (6) 113.6 (6) 135.6 (6) 110.7 (7) 116.2 (6) 111.8 (5) 137.1 (5) 110.9 (7) 123.6 (7) 114.0 (7) 122.3 (8) 115.2 (8) 126.6 (8) 118.2 (9)
110.4 (7) 126.8 (8) 122.8 (9) 115 (1) 125 (1) 119 (1) 122 (1) 119.4 (9) 118 (1) 121.2 (7) 114.1 (6) 124.7 (8) 114.3 (7) 127.7 (8) 118.0 (8) 111.1 (6) 125.7 (7) 123.1 (8) 116.2 (8) 122.2 (9) 121.5 (9) 118.7 (9) 122.8 (9) 118 (1) 125 (2) 89 (1)
schemes for the three compounds. Bond distances and angles are presented in Tables V and VI for 1, in Tables VI1 and VI11 for 2, and in Tables IX and X for 3. The strucure of 1 was solved in the monoclinic space group P2Jn. Each molecule occupies a general position within the unit cell, and as a result the molecule has no crystallographically imposed symmetry. The molecule is, therfore, not restricted to the totally eclipsed configuration but is free to adopt a staggered configuration. There does appear to be a slight tendency for this to occur, since there is an average 1.85” twist of the ligands about the metal-metal bond. (See Table XI). However, the magnitude of the twist is about at the level of the uncertainties and has no chemical significance. Each molecule has three ambt ligands and one acetate ligand. The two ambt ligands that are opposite to each other are related by a virtual mirror plane containing the other thiazole ligand (which has the opposite orientation) and the acetate ligand. The virtual symmetry of the molecule is thus derived solely from one mirror plane, The two T H F molecules per molecule of complex occupy the voids between the molecules, and there are no axially coordinated ligands. As is typical of T H F molecules occupying such positions, they are poorly defined under refinement and have extremely high temperature factors. Whether this is a result of partial occupancy, high thermal
Cotton and Ilsley
516 Inorganic Chemistry, Vol. 20, No. 2, 1981 Table IX. Bond Distances for Mo,(acbt),.THF (3) atoms dist, A atoms 2.117 (1) 2.131 (4) 2.191 (3) 2.137 (4) 2.216 (3) 1.742 ( 5 ) 1.728 ( 5 ) 1.768 (4) 1.745 ( 5 ) 1.766 ( 5 ) 1.721 ( 5 ) 1.309 (6) 1.360 (6) 1.390 (6) 1.289 (6) 1.362 (6) 1.395 (6) 1.414 (6) 1.383 (6)
dist, A 1.376 (7) 1.397 (7) 1.376 (7) 1.412 (7) 1.408 (7) 1.374 (7) 1.405 (7) 1.383 (8) 1.408 (8) 1.394 (8) 1.41 (1) 1.41 (1) 1.5 3 (2) 1 5 0 (2) 1 5 8 (2) 3.192 (2) 3516 (2) 3.257 (2)
Table X. Bond Angles for Mo,(acbt),.ZTI-IF (3) angle, angte, atoms deg- . deg MO(l)'-MO(l)-N(l)' 9 2 5 (1) C(102~-0(101)C(105) 115.6 (7) -N(2) 93.09 (9) - ~ i 3 j 93.4 6). N(4)' 91.74 (9) N(l)'-Mo(l)-N(2) 173.1 (1) -N(3) 86.6 (1) -N(4)' 91.5 (1) N(2)-Mo(l)-N(3) 89.2 (1) -N(4)' 92.2 (1) N(3)-Mo(l)-N(4)' 174.6 (1) C(1)-S (114331 89.6 (2) C(S)-S(2)-C(lO) 90.3 (2) MO(l)'-N(l)4(1) 117.9 (3) Mo(l)-N(2)4(1) 112.9 (3) C ( 2 ) 136.7 (3) C(l)-NO)C(Z) 110.3 (4) Mo(l)-N(3)-C(8) 118.8 (3) Mo(l)-N(4)
