Pyridinium compounds, a synthesis method therefor, metal or metal alloy plating baths containing said pyridinium compounds and a method for use of said metal or metal alloy plating baths

1. A compound comprising a building block according to formula (I)

wherein each A represents a unit independently selected from the following formulae (A1) and (A2)

wherein

R a1 , R a2 , R a3 and R a5 are each selected independently from the group consisting of C1-C12-alkanediyl and —(CH 2 ) c —[CH(R a6 )—CH 2 —O] d —(CH 2 ) e — wherein c is an integer ranging from 0 to 3; d is an integer ranging from 1 to 100; e is an integer ranging from 1 to 3;

each R a6 is independently from each other selected from the group consisting of hydrogen, alkyl, aryl and aralkyl;

each R a4 is independently selected from the group consisting of alkanediyl, arenediyl and —(CH 2 ) f —[CH(R a7 )—CH 2 —O] g —(CH 2 ) h —, wherein f is an integer ranging from 0 to 3; g is an integer ranging from 1 to 100; h is an integer ranging from 1 to 3; each R a7 is independently from each other selected from the group consisting of hydrogen, alkyl, aryl and aralkyl;

each X 1 and X 2 are independently selected from the group consisting of

wherein Z is selected from —CH 2 —, O, S; z and z′ are integers independently ranging from 1 to 6, each R a8 and R a9 are independently selected from the group consisting of hydrogen, alkyl, aryl, aralkyl and —CH 2 —CH 2 —(OCH 2 CH 2 ) y —OH wherein y is an integer from 1 to 4;

each Y 1 , Y 2 and Y 3 are independently selected from the group consisting of O and) N(R a10 ) wherein each R a10 is independently selected from the group consisting of hydrogen, alkyl, aryl and aralkyl;

a is an integer ranging from 1 to 40; and

each D is independently selected from the group consisting of —CH 2 —CH(OH)—CH 2 —, —CH 2 —CH(SH)—CH 2 —, —(CH 2 ) i —[CH(R d1 )—CH 2 —O] j —(CH 2 ) k — and —CH 2 —CH(OH)—(CH 2 ) l —[CH(R d2 )—CH 2 —O] m —(CH 2 ) n —CH(OH)—CH 2 —

wherein i is an integer ranging from 0 to 3; j is an integer ranging from 1 to 100; k is an integer ranging from 1 to 3; each R d1 is independently from each other selected from the group consisting of hydrogen, alkyl, aryl and aralkyl; l is an integer ranging from 1 to 3; m is an integer ranging from 1 to 100; n is an integer ranging from 1 to 3; each R d2 is independently from each other selected from the group consisting of hydrogen, alkyl, aryl and aralkyl.

2. The compound according to claim 1 wherein each R a1 , R a2 , R a3 and R a5 are independently selected from 1,1-methylene (—CH 2 —), 1,2-ethylene (—CH 2 —CH 2 —), 1,3-propylene (—CH 2 —CH 2 —CH 2 —), —(CH 2 ) 2 —O—(CH 2 ) 2 — and —(CH 2 ) 2 —O—(CH 2 ) 2 —O—(CH 2 ) 2 —.

3. The compound according to claim 1 wherein X 1 and X 2 are

4. The compound according to claim 1 wherein each D is —(CH 2 ) i —[CH(R d1 )—CH 2 —O] j —(CH 2 ) k — wherein each i is 2 or 3; each j is an integer ranging from 1 to 25, each k is an integer ranging from 2 to 3 and each R d1 is independently selected from the group consisting of hydrogen and C1-C4-alkyl.

5. The compound according to claim 1 wherein R a1 to R a5 are free of nitrogen atoms.

6. The compound according to claim 3 wherein at least one A is selected to be a unit represented by formula (A1-1) or (A1-2)

7. The compound according to claim 6 wherein all A are selected to be a unit represented by formula (A1-1) or (A1-2)

8. The compound according to claim 1 wherein its weight average molecular mass M w ranges from 250 to 10000 g/mol.

9. A method of synthesizing a compound claim 1 characterized in that at least one starting material represented by one of the following formulae (M1) and M2)

wherein

R m1 , R m2 , R m3 and R m5 are each selected independently from the group consisting of C1-C12-alkanediyl and —(CH 2 ) α —[CH(R m6 )—CH 2 —O] β —(CH 2 ) X — wherein α is an integer ranging from 0 to 3; β is an integer ranging from 1 to 100; X is an integer ranging from 1 to 3; each R m6 is independently from each other selected from the group consisting of hydrogen, alkyl, aryl and aralkyl;

each R m4 is independently selected from the group consisting of alkanediyl, arenediyl and —(CH 2 ) δ —[CH(R m7 )—CH 2 —O] ε —(CH 2 ) ϕ —, wherein δ is an integer ranging from 0 to 3; ε is an integer ranging from 1 to 100; ϕ is an integer ranging from 1 to 3; each R m7 is independently from each other selected from the group consisting of hydrogen, alkyl, aryl and aralkyl;

each of M 1 , M 3 and M 4 is independently selected from the group consisting of O and N(R m10 ) wherein each R m10 is independently selected from the group consisting of hydrogen, alkyl, aryl and aralkyl; and

each of M 2 and M 5 is independently selected from the group consisting of

wherein Z is selected from —CH 2 —, O, ζ and ζ′ are integers independently ranging from 1 to 6, each R m8 and R m9 are independently selected from the group consisting of hydrogen, alkyl, aryl, aralkyl and —CH 2 —CH 2 —(OCH 2 CH 2 ) ψ —OH wherein ψ is an integer from 1 to 4

is reacted

with one or more of the following compounds (B1) to (B4)

wherein

each LG is independently selected from the group consisting of triflate, nonaflate, alkylsulfonates, arylsulfonates and halides;

ι is an integer ranging from 0 to 3; φ is an integer ranging from 1 to 100; κ is an integer ranging from 1 to 3; each R n1 is independently from each other selected from the group consisting of hydrogen, alkyl, aryl and aralkyl; λ is an integer ranging from 1 to 3; μ is an integer ranging from 1 to 100; ν is an integer ranging from 1 to 3; each R n2 is independently from each other selected from the group consisting of hydrogen, alkyl, aryl and aralkyl.

10. A metal or metal alloy plating bath comprising at least one type of reducible metal ions characterized in that said metal or metal alloy plating bath comprises at least one compound according to claim 1 .

11. The metal or metal alloy plating bath according to claim 10 wherein the at least one type of reducible metal ions are copper ions.

12. The metal or metal alloy plating bath according to claim 11 wherein the concentration of the at least one compound in the metal or metal alloy plating bath ranges from 0.01 mg/L to 1000 mg/L.

13. A method for deposition of metal or metal alloy onto at least one surface of a substrate comprising the steps

(i) providing a substrate,

(ii) contacting the surface of the substrate with an aqueous metal or metal alloy plating bath according to claim 10 , and

(iii) optionally, applying an electrical current between the substrate and at least one anode,

and thereby depositing a metal or metal alloy on at least a portion of the surface of a substrate.

14. The method of claim 13 wherein the substrate is selected from the group consisting of printed circuit boards, IC substrates, circuit carriers, interconnect devices, semiconducting wafers and glass substrates.

15. The method of claim 13 wherein the metal or metal alloy is copper or a copper alloy.