Cocrystallized complex

The reaction between Bul2Si(OH)2 and Cl4Sn affords, after workup and crystallization from CH2C12, the tin complex 51 containing a bridging But2Si(OH)2 molecule, which is cocrystallized with (H0Bu 2Si)20, the structure of which is described in Section IV,D,1 (272). 

Finally, the tris(pyrazolyl)hydroborato ligand system has also provided an interesting example in which a crystallographic site is disordered between a vacancy and a chain of three atoms. Thus, the x-ray structure of the cobalt complex [TpAnt]CoNCS (Ant = 9-anthryl) revealed the presence of the cocrystallized thallium derivative... 

Only molecular S7 and Se7 are firmly known, yet only the former has been characterized by X-ray analysis. However, Re complexes of Se7 are known55,56 and the neutral Se7 homocycle cocrystallized with salts of polyselenides.57,58 S7+ is thought to be present in S02 solutions of sulfur cations however, this is an unproven but likely hypothesis. Other than that, only the structures of Sig2+ and Se172+ contain E7 homocycles (see there). 

The condnctivity measnrements indicate that when di-iodine is added to a solution of BZIM (5) (D=S), initially both the nentral (I) and the ionic (Ila) compounds are formed as it is shown in Scheme 13.3A. Fnrther addition of di-iodine results to the ionic complex (Ila). In the case of NMBZT (Scheme 13.3B) a cocrystallization of both the spoke and iodoninm complexes takes place prodncing only the iodonium complex, in excess of I. ... 

While the x-ray structure of native Factor Xa has been reported [4] the nature of its crystal packing, specifically the fact that the active site of one Factor Xa molecule is blocked by the N-terminus of a second resulting in a continuous polymeric structure, apparently has precluded diffusing inhibitors into the preformed crystals to obtain complexes. Complexes with inhibitors cocrystallized with Factor Xa also have not been reported [81]. Thus, efforts to do structure-based design with this enzyme have relied on molecular modeling. 

The complex [(en)2Cr(OH)2Co(en)2](S206)2 has been prepared by heating the cocrystallized optically active dithionates (equation 30).445 It is an internal active racemate because the chiral centres are different, and it contains Crra in a dinuclear system not subject to magnetic interaction so that the ESR spectrum is simple. 

All the examples so far have been homonuclear. Complexes (14) provide examples of hetero-nuclear di- -OH cations, with M = Cu, Mn, Co, Ni or Zn, in solution.73 NiI+/Al3+ dimers with di- -OH have been characterized in the solid state, and may well also exist in solution.74 Although cocrystallization of cobalt and chromium hydroxo complexes normally gives the statistically expected mixture of Co2, Cr2 and CoCr di-/i-OH species (difficult to separate), if optically active starting materials are used a very high yield of the mixed dinuclear species [(en)2Cr(jt-OH)2Co(en)2]4+ can be obtained. 

---