The invention relates to new compounds of Formula 1 : [(O3/2)Si CH2CH2SX]a [Si(O4/2)]b[Si(O3/2V)]C wherein X is selected from CH2A,[CH2CH2NR1]pR2, CHCOX1CH2COX2,(CH2)eCO Y[CO(CH2)eSCH2CH2Si(O3/2)]m[CO (CH2)eSH]n wherein A is the residue of an amino acid or derivative or salt of an amino acid of formula CHNR1R2COX3 R1 and R2 are independently selected from hydrogen, C1-20alkyl, and C1-20alkylaryl C1-12acyl R is selected from hydrogen, metal ion, C1-5alkyl, P is 1 to 100 and e is 1 or 2 X1 and X2 are independently selected from OR and NR1R2 X3 is selected from OR, NR1R2 or known amino acids and proteins or derivatives thereof and Y is the residue of polyol having z or fewer hydroxyl groups substituted and m+n+1 is less than or equal to z the free valences of the silicate oxygen atoms are saturated by one or more of silicon atoms of other groups of Formula 1, hydrogen, a linear or branched C1-12-alkyl group or by end groups R33M1O1/2 or by cross-linking bridge members or by polymer chains R3qM1(OR4)gOk/2 or AI(OR4)3-hOh/2 or R3AI(OR4)2-rO1/2 where M1 is Si or Ti R4 is a linear or branched C1-40, an aryl or C1-40-alkylaryl group and R3 is a linear or branched C1-40- alkyl group or an aryl or C1-40-alkylaryl group k is an integer from 1 to 3 and q is an integer from 1 to 2 and g is an integer from 0 to 2 such that g + k + q = 4 h is an integer from 1 to 3 and r is an integer from 1 to 2 or other known oxo metal bridging systems where the metal is zirconium, boron, magnesium, iron, nickel or a lanthanide and the integers a, b and c are such that i) the ratio of a:b is from 0.00001 to 100,000 and in the formula AaBbCc both A and B are always present, and ii) when C is present the ratio of c to a+b varies from 0.00001 to 100,000. The free valences of the silicate oxygen atoms are saturated by one or more of silicon atoms of other groups of Formula 1 , hydrogen, a linear or branched alkyl groups or by end groups, cross-linking bridge members or by polymer chains containing s
