ALKYNOL AND ALKYNEDIOL FUNCTIONALIZED ZIR CONOCENE COMPOUNDS - SYNTHESIS, STRUCTURE AND REACTIVITY

The reaction of [Zr]Cl-2 (1) {[Zr] = (eta(5)-C(5)H(4)SiMe(3))(2)Zr} wi th HO(CR(2))(n)C=CH (2a: R = H, n = 2; 2b: R = H, n = 4; 2c: R = CH3, n = 1) or HOCH2C=CCH2OH (2d) yields, depending on the nature of the ba ses used [1,4-diazabicyclo[2.2.2]octane (DABCO) or NEt(3)], different substitution products. On treatment of 1 with 2a or 2b in toluene in t he presence of DABCO, the sigma-alkynol-substituted zirconocenechlorid es [Zr](CI)[O(CH2)(n)C=CH] (3a: n = 2; 3b: n = 4) are formed. Moreover , zirconocene sigma-dialkynols [Zr][O(CR(2))(n)C=CH](2) (4a: R = H, n = 2; 4b: R = H, n = 4; 4c: R = CH3, n = 1) can be obtained by treatmen t of compounds 1, 3a or 3b with 2a-2c in NEt(3). When 2d is reacted wi th two equivalents of 1 in the presence of DABCO, the product isolated is (Cl)[Zr](mu-OCH2C=CCH2O)[Zr](Cl) (5), while in NEt(3) as solvent c yclic [Zr](mu-OCH2C=CCH2O)(2)[Zr] (6) is obtained. The chemical behavi our of compounds 3 and 4 is discussed. The reaction of [Zr](Cl)[O(CH2) (2)C=CH] (3a) with [CuO(2)CMe](4) (7) yields [Zr](Cl)(mu-O(2)CMe) (8) by elimination of [CuO(CH2)(2)C=CH](n). Treatment of compounds 3a, 4a or 4c with Co-2(CO)(8) (9) affords [ZR](Cl){[eta(2)-O(CH2)(2)C=CH]Co-2 (2)(CO)(6)] (10), [Zr]{[eta(2)-O(CH2)(2)C=CH]Co-2(CO)(6)}(2) (11a) or [Zr]{[eta(2)-OCMe(2)C=CH]Co-2(CO)(6)}(2) (11b) respectively. in each o f these compounds the HC=C building block is eta(2)-coordinated to a C o-2(CO)(6) fragment. Treatment of complexes 3a, 4b, 10 or 11 with HCl( aq) produces [Zr]Cl-2 (1) and 2a or 2b [reaction of 3 or 4 with HCl(aq )] or [Zr]Cl-2 (1) and [eta(2)-HO(CH2)(2)C=CH]Co-2(CO)(6) (12a) or (et a(2)-HOCMe(2)C=CH)Co-2(CO)(6) (12b) [reaction of 10 or 11 with HCl(aq) ]. The solid state structures of compounds [Zr](Cl)[O(CH2)(2)C=CH] (3a ), (Cl)[Zr](mu-OCH2C=CCH2O)[Zr](Cl) (5) and [Zr]{[eta(2)-OCMe(2)C=CH]C o-2(CO)(6)}(2) (11b) are reported. 3a crystallizes in the rhombic spac e group Pnma with cell constants a = 813.1(3), b = 1523.7(5), c = 1850 .0(6) pm, V = 2292.0(9) x 10(6) pm(3) and Z = 4. Crystals of 5 and 11b are monoclinic. Compound 5: space group Pc with a = 1290.8(6), b = 25 82(1), c = 760.1(3) pm, beta = 73.15(3)degrees, V = 2424(2) x 10(6) pm (3) and Z = 2. Compound 11b: space groupP2(1)/n with a = 1461.0(6), b = 2057(1), c = 1528.4(6) pm, beta = 96.06(3)degrees, V = 4567(3) x 10( 6) pm(3) and Z = 4.