Novel doubly bridged metallocene complexes (Me2Si)(Me2C)(C5H3)(2)MCl2 (M = Ti(4), Zr(8)), were synthesized by reactions of the dilithium salt of the corresponding ligand with MCl4. When (Me2Si)(Me2C)(C5H3SnMe3)(2) compound was used instead of the corresponding dilithium salt, the complex 4 was obtained in high yield. The structures were determined by X-ray analysis (4: triclinic, P(- 1), a = 9.063(2), b = 11.238(2), c = 8.956(2) angstrom, alpha= 91.29(1), beta = 118.56(1), gamma = 77.66(2)degrees, Z = 2; 8: monoclinic, P2(1) In, a = 12.743(2), b = 9.149(3), c = 14.678(2)angstrom, beta = 11 0.62(1)degrees, Z=4). As expected, each of them showed the smallest bite-angle (4: 120 degrees; 8: 114 degrees) in the bis(cyclopentadienyl) type of Ti or Zr complexes. Singly bridged and doubly bridged metallocenes were synthesized to study the influence of the bite-angle on ethylene/1-octene copolymerization. Copolymerizations of ethylene/1-octene were carried out using these metallocenes in the presence of cocatalyst (methylaluminoxane (MAO) or [PhNMe2H][B(C6F5)(4)]/triisobutylaluminium (AI(i-Bu)(3))). These complexes showed high 1-octene incorporation abilities. (c) 2007 Elsevier B.V. All rights reserved.