Context : To better understand the initial conditions of the high-mass star formation process , it is crucial to study at high-angular resolution the morphology , the kinematics , and eventually the interactions of the coldest condensations associated with intermediate-/high-mass star forming regions .

Aims : The paper studies the cold condensations in the intermediate-/high-mass proto-cluster IRAS 05345+3157 , focusing the attention on the interaction with the other objects in the cluster .

Methods : We have performed millimeter high-angular resolution observations , both in the continuum and several molecular lines , with the PdBI and the SMA .
In a recent paper , we have already published part of these data .
The main finding of that work was the detection of two cold and dense gaseous condensations , called N and S ( masses \sim 2 and \sim 9 M _ { \odot } ) , characterised by high values of the deuterium fractionation ( \sim 0.1 in both cores ) obtained from the column density ratio N ( N _ { 2 } D ^ { + } ) / N ( N _ { 2 } H ^ { + } ) .
In this paper , we present a full report of the observations , and a complete analysis of the data obtained .

Results : The millimeter maps reveal the presence of 3 cores inside the interferometers primary beam , called C1-a , C1-b and C2 .
None of them are associated with cores N and S. C1-b is very likely associated with a newly formed early-B ZAMS star embedded inside a hot-core , while C1-a is more likely associated with a class 0 intermediate-mass protostar .
The nature of C2 is unclear .
Both C1-a and C1-b are good candidates as driving sources of a powerful ^ { 12 } CO outflow , which strongly interacts with N , as demonstrated by the velocity gradient of the gas along this condensation .
The N _ { 2 } H ^ { + } linewidths are between \sim 1 and 2 km s ^ { -1 } in the region where the continuum cores are located , and smaller ( \sim 0.5 - 1.5 km s ^ { -1 } ) towards N and S , indicating that the gas in the deuterated condensations is more quiescent than that associated with the continuum sources .
This is consistent with the fact that they are still in the pre–stellar phase and hence the star formation process has not yet taken place in there .

Conclusions : The study of the gas kinematics across the source indicates a tight interaction between the deuterated condensations and the sources embedded in the millimeter cores .
For the nature of N and S , we propose two scenarios : they can be low-mass pre–stellar condensations or ’ seeds ’ of future high-mass star ( s ) .
From these data however it is not possible to establish how the turbulence triggered by the neghbouring cluster of protostars can influence the evolution of the condensations .