NOVELTY - Calamitic mesogenic compounds are new.    USE - Calamitic mesogenic compounds are used in a polymerizable liquid crystal (LC) formulation and a birefringent polymer film. The compounds, the LC formulations and the polymer films are used in optical, electronic and electrooptical components and devices, preferably in optical films, retarders or compensators having negative optical dispersion. The devices or components are electrooptical displays, LCDs, optical films, polarizers, compensators, beam splitters, reflective films, alignment layers, color filters, holographic elements, hot stamping foils, colored images, decorative or security markings, LC pigments, adhesives, non-linear optic (NLO) devices, optical information storage devices, electronic devices, organic semiconductors, organic field effect transistors (OFET), integrated circuits (IC), thin film transistors (TFT), radio frequency identification (RFID) tags, organic light emitting diodes (OLED), organic light emitting transistors (OLET), electroluminescent displays, organic photovoltaic (OPV) devices, organic solar cells (O-SC), organic laser diodes (O-laser), organic integrated circuits (O-IC), lighting devices, sensor devices, electrode materials, photoconductors, photodetectors, electrophotographic recording devices, capacitors, charge injection layers, Schottky diodes, planarizing layers, antistatic films, conducting substrates, conducting patterns, photoconductors, electrophotographic applications, electrophotographic recording, organic memory devices, biosensors, biochips, optoelectronic devices requiring similar phase shift at multiple wavelengths, combined compact disc (CD)/DVD/high density (HD)-DVD/Blu-ray disc (RTM: high-density optical disc format), readings, writing re-writing data storage systems, or cameras. The optical component is an optically uniaxial film from an A-plate, C-plate, negative C-plate or O-plate, a twisted optical retarder, a twisted quarter wave foil (QWF), an optically biaxial film, an achromatic retarder, an achromatic QWF or half wave foil (HWF), a film having a cholesteric, smectic, nematic or blue phase, a film having homeotropic, splayed, tilted, planar or blue-phase alignment, which is uniformly oriented or exhibits a pattern of different orientations; or an optical compensation film for viewing angle enhancement of LCD's, a component in brightness enhancement films, or an achromatic element in reflective or transflective LCD's. (all claimed)    ADVANTAGE - The calamitic mesogenic compounds demonstrate reduced or negative dispersion, are also available at reduced costs, and have improved properties (e.g., solubility and thermal properties).    DETAILED DESCRIPTION - Calamitic mesogenic compounds of formula D(-(B')q-M)z (I) are new.    D=discotic group, or forms a discotic group together with (B')q;    z=3-10;    B'=bivalent group having high polarizability, preferably -C?=C-, -CY1=CY2- or optionally substituted aromatic or heteroaromatic groups;    Y1, Y2=H, F, Cl, CN, or R0;    q=0, or 1-10;    M=group of formula R1-(A1-Z1)m-U1((Z2-A2)n-R2)- (II);    U1=group of formula (a), (b) or (c) including their mirror images, where (i) the ring U1 is bonded to the group -(B')q- via the axial bond, (ii) one or two non-adjacent CH2 groups in these rings are optionally replaced by O and/or S, and (iii) the ring U1 is optionally substituted;    Q1, Q2 =CH or SiH;    Q3=C or Si;    A1, A2=non-aromatic, aromatic or heteroaromatic carbocyclic or heterocyclic groups, which are optionally substituted, where -(A1-Z1)m-U1-(Z2-A2)n- does not contain more aromatic groups than non-aromatic groups and preferably does not contain more than one aromatic group;    Z1, Z2=-O-, -S-, -CO-, -COO-, -OCO-, -O-COO-, -CO-NR0-, -NR0-CO-, -NR0-CO-NR0-, -OCH2-, -CH2O-, -SCH2-, -CH2S-, -CF2O-, -OCF2-, -CF2S-, -SCF2-, -CH2CH2-, -(CH2)3-, -(CH2)4-, -CF2CH2-, -CH2CF2-, -CF2CF2-, -CH=CH-, -CY1=CY2-, -CH=N-, -N=CH-, -N=N-, -CH=CR0-, -C?=C-, -CH=CH-COO-, -OCO-CH=CH-, CR0R00 or a single bond;    R0, R00=H or 1-12C alkyl;    m, n=0, 1, 2, 3, or 4;    m+n=greater than 0;    R1-R3=H, halo, -CN, -NC, -NCO, -NCS, -OCN, -SCN, -C(=O)NR0R00, -C(=O)X0, -C(=O)R0, -NH2, -NR0R00, -SH, -SR0, -SO3H, -SO2R0, -OH, -NO2, -CF3, -SF5, P'-Sp-, optionally substituted silyl, or carbyl or hydrocarbyl with 1-40C that is optionally substituted and optionally comprises one or more hetero atoms or denote P' or P'-Sp, or is substituted by P' or P'-Sp;    P'=polymerizable group; and    Sp=spacer group or single bond.    INDEPENDENT CLAIMS are included for:    (1) a polymerizable liquid crystal (LC) formulation, comprising one or more calamitic mesogenic compounds; and one or more further compounds, where at least one of the compounds is polymerizable;    (2) a birefringent polymer film obtainable by polymerizing the calamitic mesogenic compound or the LC formulation in its LC phase in an oriented state in form of a thin film;    (3) an optical, electronic or electrooptical component or device, comprising the calamitic mesogenic compound, the LC formulation or the polymer film; and    (4) a method of preparing the calamitic mesogenic compounds.