NOVELTY - Pyridine compound (I) is new.    USE - The compound is used for electrophotographic photoreceptors, photoelectric converters, solar cells, image sensors, dye lasers, and electroluminescent devices (claimed). The electroluminescent devices are used for full color display panels, e.g. mobile phones, televisions, or personal computer screens.    ADVANTAGE - The compound has excellent electric-field-applied light emission characteristics, excellent in the injection of holes from metal electrode and transportation of holes. The electroluminescent device is stable against heat and electric current, gives usable light emission brightness at low actuation voltage, and decreases problematic deterioration.    DETAILED DESCRIPTION - Pyridine compound of formula (I) is new.    W', X, Y'=formula (2);    R11-R13, R15-R17, R41, R42, R44-R47, R11'-R13', R15'-R17', R41', R42', R44'-R47'=H, E, 6-18C aryl, 6-18C aryl that is substituted by G, 1-18C alkyl that is substituted by E and/or interrupted by D, 7-18C aralkyl, or 7-18C aralkyl that is substituted by G;    R18, R19=1-18C alkyl, 1-18C alkoxy, 6-18C aryl, or 7-18C aralkyl;    R30-R33, R49, R50=H, 1-18C alkyl, 1-18C alkyl, which is substituted by E and/or interrupted by D; E; 6-8C aryl; 6-18C aryl that is substituted by G;    R14=H, 2-30C heteroaryl or 2-30C heteroaryl which is substituted by G, -NR70R71; 6-30C aryl, or 6-30C aryl which is substituted by G, 1-18C alkyl; or 1-18C alkyl which is substituted by E and/or interrupted by D (preferably formula (7)-(9));    R21-R27=H, E, 1-18C alkyl, 1-18C alkyl that is substituted by E and interrupted by D; E; 7-18C aralkyl; 7-18C aralkyl substituted by G;    R43, R48=H; E; 1-18C aralkyl substituted by E and/or interrupted by D; 2-30C heteroaryl; or 2-30C heteroaryl, which is substituted by G; -NR70R71;    R70, R71=6-18C aryl that can be substituted by G; 7-18C aralkyl; 7-18C aralkyl that is substituted by G, or is a condensed 10-30C aryl group of naphthyl, as-indacnyl, s-indacenyl, acenaphthyl, fluorenyl, phenalenyl, phenanthrenyl, anthracenyl, fluoranthenyl, triphenlenyl, chrysenyl, naphthacene, picenyl, perylenyl, pentaphenyl, hexacenyl, or pyrenyl that can be substituted by group(s) G;    D=-CO-, -COO-, -OCOO-, -S-, -SO-, -SO 2-, -O-, -NR5-, SiR61R62-, -POR5-, -CR63=CR64-; or -CC-;    E=-OR5, -SR5, -NR5R6, -COR8, -COOR7, -CONR5R6, -CN, or halo;    G=E, or 1-18C;    R5, R6=6-18C aryl; 6-18C aryl which is substituted by 1-18C alkyl; 1-18C alkyl optionally interrupted by -O-; or formula (10) or (11);    R7=6-18C aryl, 6-18C aryl which is substituted by 1-18C alkyl, 1-18C alkyl, or 1-18C alkyl which is interrupted by -O-;    R8=7-12C alkylaryl, 1-18C alkyl, or 1-18C alkyl which is interrupted by -O-;    R61, R62=6-18C aryl, which can be optionally substituted by 1-18C alkyl, 1-18C alkyl, or 1-18C alkyl which is interrupted by -O-;    R63, R64=H, 6-18C aryl which can be optionally substituted by 1-18C alkyl, 1-18C alkyl, or 1-18C alkyl which is interrupted by -O-.    The groups W', X, and/or Y' are 10-30C aryl of naphthyl, as-indacnyl, s-indacenyl, acenaphthyl, fluorenyl, phenalenyl, phenanthrenyl, anthracenyl, fluoranthenyl, triphenlenyl, chrysenyl, naphthacen, picenyl, perylenyl, pentaphenyl, hexacenyl, or pyrenyl, which can be substituted by group(s) G; and the other groups are aryl or heteroaryl (preferably formula (3), (4), or (2). R11' and R12, R12' and R13, R15' and R16, R16' and R16, R16' and R17, R44' and R46 and/or R45' and R47 are divalent group L1 of O, S, =CR18R19, =SiR18R19, or formula (5).    R11 and R11', R12 and R12', R13 and R13', R13' and R14, R14 and R15, R15 and R15', R16 and R16', R17' and R17, R41 and R41', R42 and R42', R42' and R43, R41' and R43, R44 and R44', R45 and R45', R46 and R46', R47 and R47', R46' and R48' and/or R47' and R48' are divalent group of formula (6).    R70 and R71 together with the nitrogen atom to which they are bonded form 5- or 6-membered ring. R5 and R6 together form 5- or 6-membered ring.    Y' is formula (12) and X and Y' are phenyl, Y' is (12), X is phenyl and W' is (13), Y' and W' are (12) and X is phenyl, W' is (12), and X is phenyl and Y' is formula (14), are excluded.    An INDEPENDENT CLAIM is also included for electroluminescent device comprising a pyridine compound.