| A series of novel bioactive organometallic materials of the type (o-EMeC 6H4)CH2MR3-nCln were synthesized to form: (1) M = Si, (2) M = Ge, (3) M = Sn, (4) M = Pb [E = S, R = Ph, n = 0], (5) n = 1, (6) n = 2 [M = Sn, R = Ph], (7) n = 0, (8) n = 1 [M = Sn, R = p-(t-BuPh)], (9) n = 0, (10) n = 1, (11) n = 2 [E = O, R = Ph]. Their crystal and molecular structures have been determined and characterized by solution NMR and X-ray crystallography. To further illustrate intramolecular interactions and to understand molecular motions in the solid state of these materials, solid-state 119Sn CPMAS NMR was performed on compounds 3-11 and compared to 119Sn solution state chemical shifts. Analysis shows that the tin atom approaches a pseudo-trigonal bipyramidal pentacoordination as a consequence of intramolecular Sn-S (3, 5-8) and Sn-O (9-11) interactions. The intramolecular Sn-S distances range from 3.699 A and 3.829 A in 3 (88% and 91.2% vdW radii), 3.062 A in 5 (73% vdW radii) and 2.994 A in 6 (71% vdW radii) whereas the Sn-O distances in 9, 10 and 11 are 3.07 A (82.9% the sum of the van der Waal radii), 2.76 A (74.5% vdW radii) and 2.92 A (78.9% vdW radii), respectively. The geometry of compound 11 is additionally complicated by an intermolecular interaction of 3.488 A between Sn in one molecule and Cl in a neighboring molecule creating a distorted octahedral geometry. Furthermore, the utility of CPMAS 119Sn NMR is again illustrated as a second crystal form of 3, 3', which is monoclinic, with one molecule in the unit cell, and a Sn-S distance of 3.973 A (94.6% vdW radii) was discovered. |
