Taking Mo~3S~4(dtp)~4.H~2O and M'(CO)~6(M'=Mo, W) as starting materials, one homo- and one hetero-tetranuclear cluster compounds [Mo~4S~4(μ-C~2H~5CO~2)~2(dtpH)(dtp)~3] 4, [Mo~3WS~4(μ-CH~3CO~2)~2 (dtpH)(dtp)~3] 5 [dtp=(EtO)~2PS~2^-; dtpH=(EtO)~2P(S)] are obtained by using [3+1] reaction mode under the carboxylic medium. Both compounds contain a [M~4S~4]^5^+ cubane-type cluster core possessing 11 cluster electrons. This kind of core result from the reduction of M'(CO)~6 whereas the (dtpH) ligands are formed by dtp groups under the presence of carboxylic acid. The crystal data are as follows 4 Mo~4S~4(C~2H~5CO~2)~2[(OC~2H~5)~2PS~2]~3[(OC~2H~5)~2P(S)SH] M~r=1400. 01, Orthorhombic Pbca, a=2.4230(8), b=2.2403(5), c=1.9131(8)nm, V=10. 385(6)nm^3, Z=8, D~c=1.79g/cm^3. F(000)=5584, μ(MoKα)=15.51cm^-^1, the values of R and R~w are 6.8% and 7.7% respectively for 2443 observed reflections. 5 Mo~3WS~4(CH~3CCO~2)~2[(OC~2H~5)~2PS~2]~3[ (OC~2H~5)~2P(S)SH] M~r=1459.87, Orthorhombic Pbca, a=2.4465(7), b=2. 1773(6), c=1.8880(8)nm, V=10.057(8)nm^3, Z=8, D~c=1.93g/cm^3, F(000) =5720, μ(MoKα)=36.92cm^-^1. The values of R and R~w are 5.9% and 6. 8% respectively for 2758 observed reflections.

Key words: CRYSTAL STRUCTURE, SYNTHESIS, MOLYBDENUM, STRUCTURE CHARACTERISTICS, X-RAY ANALYSIS