Jobject to Jarray

I want to add my json Object to my Json array this it work ok
But the data in the Json array its be weird
my joson object like this

and my json array like this

I used this methode to add my Jobject to my Jarray

in the assin activity

Jarray = JArray.FromObject(jArrayToSendToIterop.Concat({jToModify.ToString.Replace(“start_nDeLaFactureVALUE”, start_nDeLaFacture.Trim).Replace(“start_dateDeLaFactureVALUE”,start_dateDeLaFacture.Trim).Replace(“start_montantDeLaFactureVALUE”,start_montantDeLaFacture.trim).Replace(“start_etatDeLaFactureVALUE”, start_etatDeLaFacture.Trim).Replace(“nSuperVALUE”,start_site.Trim).Replace(“nHyperVALUE”,"")}).ToArray)

thank you in advance