The Cl substitution reactions of the N/N (1-3) and N/O (4 and 5) spirocyclic monoferrocenylphosphazenes with 1,4-dioxa-8-azaspiro [4,5]decane (DASD) produce the mono-(1a-5a), geminal-(1b-5b) and tetrakis-DASD-substituted ferrocenylspirocyclotriphosphazenes (1c-5c). The mono-and geminal-DASDsubstituted phosphazenes have two and one stereogenic P-centers, respectively. The structures of the compounds were established by spectroscopic techniques.The molecular structures of 3a and 2b were evaluated using X-ray crystallography. Additionally, the ultrathin and highly ordered Langmuir-Blodgett (LB) films of 3a and 2b were also prepared. The characterizations of the LB films were done using p-polarized grazing angle (GAIR) and horizontal attenuated total reflectance (HATR) techniques. On the other hand, the antimicrobial activities of the eight phosphazene derivatives against G(+) and G(-) bacteria and fungi were investigated. Furthermore, the interactions between the compounds and plasmid DNA were studied by agarose gel electrophoresis. isomers may cause to the possibilities of optical isomers.On the other hand, phosphazene derivatives and polyorganophosphazenes are very useful compounds in technological and medicinal areas. They are used as flame retardant additives, [5] electrolytes for lithiumion batteries, [6,7] liquid crystals, [8,9] lubricants, [10] fluorescence chemosensor [11,12] and elastomers. [13] Recently, cyclotriphosphazene derivatives have also attracted a quite of interest for the preparation of the selective anticancer agents, [14] antibacterial and antifungal reagents, [15] and biomedical materials such as synthetic bones. [16] Furthermore, the potential anticancer activities of some of the mono and polyamino substituted cyclotriphosphazenes were reported. [17,18] Besides, the ultrathin films of the obtained inorganic or organic compounds have attracted much interest for applications as industrial materials, as well, such as detectors, sensors, and electronic circuit components. [19] The thin films were prepared using a solid substrate with different methods e.g. thermal evaporation, adsorption from solution, electrodeposition, sputtering, self-assembly molecular beam epitaxy, and Langmuir-Blodgett (LB) techniques. [20,21] There is only one report in the literature about the LB thin films of the phosphazene derivatives published by our group. [22] This study focused on the consecutive Cl replacement reactions of the tetrachloro monoferrocenylphosphazenes (1-5) with DASD for the aim of the obtaining of electronrich reservoir phosphazenes. Thereof, the mono-(1a-5a), geminal (1b-5b) and tetra-DASD-substituted (1c-5c) ferrocenylphosphazenes were synthesized by the reaction of 1-5 with DASD. In addition, the successive substitution reactions of Cl atoms from the pendant armed tetrachloroferrocenylphosphazenes (1-5) emerges a number of different possibilities in terms of regio-and stereoisomer selections. Eventually, we strongly stated that these compounds have been synthesized to investigate their biol...