Covalent titanium(IV)-aryloxide network materials: 4,4 '-biphenoxide 3D and polyphenolic 2D motifs

The three- and two-dimensional covalent metal-organic network (CMON) compou nds {[Ti (mu(1,6):eta(2),eta(1)-4,4'-OC12H8O)(0.5) (mu(1,6):eta(2),eta(1)-4 ,4'-OC12H8O) ((OPr)-Pr-i)((HOPr)-Pr-i)](2) . THF}(n) (1) and {[Ti(mu(1,3)-1 ,3-OC6H4O) (mu-1,3-OC6H4OH)(1,3-OC6H4OH) ((HOPr)-Pr-i)](2)}(n) (2) were syn thesized by treatment of Ti((OPr)-Pr-i)(4) with 4,4'-dihydroxybiphenyl in T HF and resorcinol in CS2, respectively, at 100 degrees C. Diffraction data was collected at the Cornell High Energy Synchrotron Source (CHESS) because of the small, weakly diffracting nature of the crystals. 1 (C26H31O5.5Ti, monoclinic, P2(1), a = 10.137(2), b = 15.988(3), c = 15.735(3), beta = 107. 76(3)degrees, Z = 4, R = 0.0858) and 2 (C21H22O7Ti, monoclinic, P2(1)/c, a =11.955(2), b = 16,275(3), c = 11.028(2), beta = 113.25(3), Z = 4, R = 0.05 50) are both based ripen similar edge-sharing bioctahedral dititanium build ing blocks, (i.e., Ti-2(mu-OAr)(2)). Six connections per dititanium unit co nstrain the structural motif of 1 to be base-centered. Four mu(1,3)-dipheno xides per dititanium core in 2 connect to provide a rectangular net, but th e regiochemistry of resorcinol ultimately restricts its dimensionality. The structures suggest design elements based on the number and geometry of con necting organic linkages. (C) 2000 Academic Press.