Ligands for pnicogen chelate complexes with a metal of subgroup VIII and use of the complexes as catalysts for hydroformylation, carbonylation, hydrocyanation or hydrogenation

A pnicogen chelate compound of the formula I

• where
• Q is a bridging group of the formula
• where
• A1 and A2 are each, independently of one another, O, S, SiRaRb, NRc or CRdRe, where
• Ra, Rb and Rc are each, independently of one another, hydrogen, alkyl, cycloalkyl, heterocycloalkyl, aryl or hetaryl,
• Rd and Re are each, independently of one another, hydrogen, alkyl, cycloalkyl, heterocycloalkyl, aryl or hetaryl or the group Rd together with a further group Rd or the group Re together with a further group Re form an intramolecular bridging group D,
• D is a divalent bridging group selected from among the, groups
• where
• R9 and R10 are each, independently of one another, hydrogen, alkyl, cycloalkyl, aryl, halogen, trifluoromethyl, carboxyl, carboxylate or cyano or are joined to one another to form a C3–C4-alkylene bridge,
• R11, R12, R13 and R14 are each, independently of one another, hydrogen, alkyl, cycloalkyl, aryl, halogen, trifluoromethyl, COOH, carboxylate, cyano, alkoxy, SO3H, sulfonate, NE1E2, alkylene-NE1E2E3+X−, acyl or nitro,
• c is 0 or 1,
• Y is a chemical bond,
• R5, R6, R7 and R8 are each, independently of one another, hydrogen, alkyl, cycloalkyl, heterocycloalkyl, aryl, hetaryl, COORf, COO−M+, SO3Rf, SO3−M+, NE1E2, NE1E2E3+X−, alkylene-NE1E2E3+X−, ORf, SRf, (CHRgCH2O)xRf, (CH2N(E1))xRf, (CH2CH2N(E1))xRf, halogen, trifluoromethyl, nitro, acyl or cyano,
• where
• Rf, E1, E2 and E3 are identical or different radicals selected from among hydrogen, alkyl, cycloalkyl and aryl,
• Rg is hydrogen, methyl or ethyl,
• M+ is a cation,
• X− is an anion and
• x is an integer from 1 to b 120,
• or
• R5 and/or R7 together with two adjacent carbon atoms of the benzene ring to which they are bound form a fused ring system having 1, 2 or 3 further rings,
• a and b are each, independently of one another, b 0 or 1,
• Pn is a pnicogen atom selected from among the elements phosphorus, arsenic or antimony,
• and
• R1, R2, R3, R4 are each, independently of one another, hetaryl, hetaryloxy, alkyl, alkoxy, aryl, aryloxy, cycloalkyl, cycloalkoxy, heterocycloalkyl, heterocycloalkoxy or an NE1E2 group, with the proviso that R1 and R3 are pyrrole groups bound via the nitrogen atom to the pnicogen atom Pn, or R1 together with R2 and/or R3 together with R4 form a divalent group E of the formula
• Py—I—W
• containing at least one pyrrole group bound via the pyrrole nitrogen to the pnicogen atom Pn,
• where
• Py is a pyrrole group,
• I is a chemical bond or O, S, SiRaRb, NRc or CRhRi,
• W is cycloalkyl, cycloalkoxy, aryl, aryloxy, hetaryl or hetaryloxy,
• and
• Rh and Ri are each, independently of one another, hydrogen, alkyl, cycloalkyl, heterocycloalkyl, aryl or hetaryl,
• or form a bispyrrole group of the formula
• Py—I—Py
• bound via the nitrogen atoms to the pnicogen atom Pn.