This thesis examines the thiourea synthetic route to 4-substitued phenylcyamamide ligands, like (4-NO 2 -pcyd), (4-Br-pcyd), (4-Cl-pcyd), (4-F-pcyd), and their physical characterization by electronic and IR spectroscopies, crystallography and theoretical methods. This is suprising as the coordinatin chemistry of phenylcyanamides should be as rich as that of other pseudohalides such az azide and thiocyanate. Indeed, the attachment of a phenyl ring to the cyanamide group adds an extra dimension not present in azide or thiocyanate ligands. An extensive ? conjugation between the cyanamide group and the phenyl ring provides an energetically favorable means by which a metal ion can couple into a conjugated organic ? system.This is demonstrated by the extraordinary ability of 1,4-dicyanamido benzene to mediate metal-metal coupling, the magnitude of which is dramatically dependent upon the nuture of both inner and outer coordination spheres. The development of novel hybrid materials that combine coordination and organic chemistry provides further impetus to explore the coordination chemistry of phenylcyanamide ligands. While the coordination chemistry of phenylcyanamide ligands is unexplored, a significant number of monoclear coordination complexes of manganese (II) have been synthesized.In this study, structure and properties of complexes [Mn(4-NO 2 -pcyd) 2 (CH 3 OH) 4 ], [Mn(4-Br-pcyd) 2 (CH 3 OH) 4 ], [Mn(4-Clpcyd) 2 (CH 3 OH) 4 ] and [Mn(4-F-pcyd) 2 (CH 3 OH) 4 ] will be reviewed that show octahedral shape with symmetry group D 4h . At last, the coordination chemistry of phenylcyanamide ligands still requires uch effort to complete. There are no examples of complexes of the early transition metals and of the middle and late transition metals, complexes of Os, Ir, Au and Zn group are unknown. A fundamental understanding of mononuclear, dinuclear and polynuclear transition metal is of key importance to design of molecular devices such as low impedance molecular wires, molecular switches, as well as the creation of novel materials with useful magnetic or optical properties. Such devices could find application in a variety of areas such as nanoscale electronics, biological probes, magnetic shield, and video display.