Abstract: This invention relates to a transition metal compound represented by the formula LMX wherein M is a Group 3 to 11 metal L is a bulky bidentate or tridentate neutral ligand that is bonded to M by two or three heteroatoms and at least one heteroatom is nitrogen; X is a substituted or unsubstituted catecholate ligand provided that the substituted catecholate ligand does not contain a 1,2-diketone functionality.

Abstract: A method and apparatus for producing a stepless 3-dimensional object by stereolithography, wherein a mathematical representation of the object is stored and dissected so as to generate a mathematical representation of a first laminate thereof, and a representative slope of the side wall surface of the first laminate at a plurality of different coordinates along the side wall surface is determined. The height of the first laminate is optimized by increasing the height whilst minimizing any deviation between the representative slope and the mathematical representation of the side wall surface. The liquid medium is irradiated with a beam of radiation at an angle representative of the uniform slope, and the irradiated liquid medium is allowed to polymerize and harden. The cured laminate is displaced relative to a surface of the liquid, and the process is repeated as required in respect of subsequent contiguous laminates.