Organic electroluminescent materials and devices

1. A compound having a metal coordination complex structure;

wherein the compound is capable of functioning as an emitter in an organic light emitting device at room temperature;

wherein the compound has the formula of Pt(L 1 )(L 2 ), each of L 1 and L 2 are a bidentate ligand, and L 1 is connected to L 2 to form a tetradentate ligand;

wherein the compound has a first substituent R 1 at one of L 1 and L 2 's periphery;

wherein the compound has a second substituent R 2 at the other of L 1 and L 2 's periphery;

wherein a first distance is the distance between the Pt and an atom in R 1 that is the farthest away from the Pt;

wherein the first distance is longer than any distance between the Pt and any other atoms in the compound;

wherein a second distance is the distance between the Pt and an atom in R 2 that is the farthest away from the Pt;

wherein when a sphere having a radius r is defined whose center is the Pt and the radius r is the smallest radius that will allow the sphere to enclose all atoms in the compound that are not part of R 1 or R 2 , the first distance and the second distance are longer than the radius r by at least 1.5 Å; and

wherein at least one of the following is true:

(1) the first and second distances are all longer than r by at least 4.3 Å; or

(2) wherein L 1 and L 2 are each independently selected from the group consisting of:

wherein each X 1 to X 17 are independently selected from the group consisting of carbon and nitrogen;

wherein X is selected from the group consisting of BR′, NR′, PR′, O, S, Se, C═O, S═O, SO 2 , CR′R″, SiR′R″, and GeR′R″;

wherein R′ and R″ are optionally fused or joined to form a ring;

wherein each R a , R b , R c , and R d may represent from mono substitution to the possible maximum number of substitution, or no substitution;

wherein R′, R″, R a , R b , R c , R d , R e are each independently selected from the group consisting of hydrogen, deuterium, halide, alkyl, cycloalkyl, heteroalkyl, arylalkyl, alkoxy, aryloxy, amino, silyl, alkenyl, cycloalkenyl, heteroalkenyl, alkynyl, aryl, heteroaryl, acyl, carbonyl, carboxylic acids, ester, nitrile, isonitrile, sulfanyl, sulfinyl, sulfonyl, phosphino, and combinations thereof; and

wherein any two R a , R b , R c , and R d are fused or joined to form a ring; and

wherein at least one of the R a , R b , R c , and R d includes R 1 .

2. The compound of claim 1 , wherein the first and second distances are all longer than r by at least 4.3 Å.

3. The compound of claim 1 , wherein R 1 is attached to an aromatic ring having a first coordination atom, R 2 is attached to an aromatic ring having a second coordination atom; and

wherein the first coordination atom is in a trans configuration to the second coordination atom relative to the Pt.

4. The compound of claim 1 , wherein the compound has a transition dipole moment axis; and

wherein an angle between the transition dipole moment axis and an axis along the first distance is less than 40°.

5. The compound of claim 1 , wherein the compound is capable of functioning as a phosphorescent emitter, a fluorescent emitter, or a delayed fluorescent emitter in an organic light emitting device at room temperature.

6. The compound of claim 1 , wherein the compound is capable of emitting light from a triplet excited state to a ground singlet state at room temperature.

7. The compound of claim 1 , wherein the compound has a platinum-carbon bond.

8. The compound of claim 1 , wherein the compound comprises at least one deuterium atom.

9. The compound of claim 1 , wherein the compound comprises a first benzene ring coordinated to the metal; and wherein the first benzene ring is fused by a second aromatic ring.

10. The compound of claim 1 ,

wherein L 1 and L 2 are each independently selected from the group consisting of:

wherein each X 1 to X 17 are independently selected from the group consisting of carbon and nitrogen;

wherein X is selected from the group consisting of BR′, NR′, PR′, O, S, Se, C═O, S═O, SO 2 , CR′R″, SiR′R″, and GeR′R″;

wherein R′ and R″ are optionally fused or joined to form a ring;

wherein each R a , R b , R c , and R d may represent from mono substitution to the possible maximum number of substitution, or no substitution;

wherein R′, R″, R a , R b , R c , R d , R e are each independently selected from the group consisting of hydrogen, deuterium, halide, alkyl, cycloalkyl, heteroalkyl, arylalkyl, alkoxy, aryloxy, amino, silyl, alkenyl, cycloalkenyl, heteroalkenyl, alkynyl, aryl, heteroaryl, acyl, carbonyl, carboxylic acids, ester, nitrile, isonitrile, sulfanyl, sulfinyl, sulfonyl, phosphino, and combinations thereof; and

wherein any two R a , R b , R c , and R d are fused or joined to form a ring; and

wherein at least one of the R a , R b , R c , and R d includes R 1 .

11. The compound of claim 10 , wherein at least one pair of substituents R a , R b , R c , and R d within the same ring are joined and fused into a ring.

12. The compound of claim 10 , wherein at least one pair of substituents R a , R b , R c , and R d between two nearby rings are joined and fused into a ring.

13. The compound of claim 1 , wherein R 1 is selected from the group consisting of:

14. An organic light emitting device (OLED) comprising:

an anode;

a cathode; and

an organic layer, disposed between the anode and the cathode, comprising a compound having a metal coordination complex structure;

wherein the compound is capable of functioning as an emitter in an organic light emitting device at room temperature;

wherein the compound has the formula of Pt(L 1 )(L 2 ), each of L 1 and L 2 are a bidentate ligand, and L 1 is connected to L 2 to form a tetradentate ligand;

wherein the compound has a first substituent R 1 at one of L 1 and L 2 's periphery;

wherein the compound has a second substituent R 2 at the other of L 1 and L 2 's periphery;

wherein a first distance is the distance between the Pt and an atom in R 1 that is the farthest away from the Pt;

wherein the first distance is longer than any distance between the metal and any other atoms in the compound;

wherein a second distance is the distance between the Pt and an atom in R 2 that is the farthest away from the Pt;

wherein when a sphere having a radius r is defined whose center is the Pt and the radius r is the smallest radius that will allow the sphere to enclose all atoms in the compound that are not part of R 1 or R 2 , the first distance and the second distance are longer than the radius r by at least 1.5 Å; and

wherein at least one of the following is true:

(1) the first and second distances are all longer than r by at least 4.3 Å; or

(2) wherein L 1 and L 2 are each independently selected from the group consisting of:

wherein each X 1 to X 17 are independently selected from the group consisting of carbon and nitrogen;

wherein X is selected from the group consisting of BR′, NR′, PR′, O, S, Se, C═O, S═O, SO, CR′R″, SiR′R″, and GeR′R″;

wherein R′ and R″ are optionally fused or joined to form a ring;

wherein each R a , R b , R c , and R d may represent from mono substitution to the possible maximum number of substitution, or no substitution;

wherein R′, R″, R a , R b , R c , R d , R e are each independently selected from the group consisting of hydrogen, deuterium, halide, alkyl, cycloalkyl, heteroalkyl, arylalkyl, alkoxy, aryloxy, amino, silyl, alkenyl, cycloalkenyl, heteroalkenyl, alkynyl, aryl, heteroaryl, acyl, carbonyl, carboxylic acids, ester, nitrile, isonitrile, sulfanyl, sulfinyl, sulfonyl, phosphino, and combinations thereof; and

wherein any two R a , R b , R c , and R d are fused or joined to form a ring; and

wherein at least one of the R a , R b , R c , and R d includes R 1 .

15. The OLED of claim 14 , wherein the compound has an intrinsic emission spectrum with a FWHM value of no more than 45 nm;

wherein the OLED has an EQE of at least 25% measured at 0.1 mA/cm 2 at room temperature when a voltage is applied across the device.

16. The OLED of claim 14 , wherein the organic layer further comprises a host, wherein host comprises at least one chemical group selected from the group consisting of triphenylene, carbazole, dibenzothiophene, dibenzofuran, dibenzoselenophene, azatriphenylene, azacarbazole, aza-dibenzothiophene, aza-dibenzofuran, and aza-dibenzoselenophene.

17. The OLED of claim 14 , wherein the compound has a horizontal dipole ratio of at least 0.7.

18. The OLED of claim 14 , wherein the organic layer further comprises a host; and

wherein the compound has a horizontal dipole ratio that is higher by at least 5% when compared to the exact same device with mCP (1,3-bis(N-carbazolyl)benzene) as host.

19. A consumer product comprising an organic light-emitting device (OLED) comprising:

an organic layer, disposed between the anode and the cathode, comprising a compound having a metal coordination complex structure;

wherein the compound is capable of functioning as an emitter in an organic light emitting device at room temperature;

wherein the compound has the formula of Pt(L 1 )(L 2 ), each of L 1 and L 2 are a bidentate ligand, and L 1 is connected to L 2 to form a tetradentate ligand;

wherein the compound has a first substituent R 1 at one of L 1 and L 2 's periphery;

wherein the compound has a second substituent R 2 at the other of L 1 and L 2 's periphery;

wherein a first distance is the distance between the Pt and an atom in R 1 that is the farthest away from the Pt;

wherein the first distance is longer than any distance between the metal and any other atoms in the compound;

wherein a second distance is the distance between the Pt and an atom in R 2 that is the farthest away from the Pt;

wherein when a sphere having a radius r is defined whose center is the Pt and the radius r is the smallest radius that will allow the sphere to enclose all atoms in the compound that are not part of R 1 or R 2 , the first distance and the second distance are longer than the radius r by at least 1.5 Å; and

wherein at least one of the following is true:

(1) the first and second distances are all longer than r by at least 4.3 Å; or

(2) wherein L 1 and L 2 are each independently selected from the group consisting of:

wherein each X 1 to X 17 are independently selected from the group consisting of carbon and nitrogen;

wherein X is selected from the group consisting of BR′, NR′, PR′, O, S, Se, C═O, S═O, SO 2 , CR′R″, SiR′R″, and GeR′R″,

wherein R′ and R″ are optionally fused or joined to form a ring;

wherein each R a , R b , R c , and R d may represent from mono substitution to the possible maximum number of substitution, or no substitution;

wherein R′, R″, R a , R b , R c , R d , R e are each independently selected from the group consisting of hydrogen, deuterium, halide, alkyl, cycloalkyl, heteroalkyl, arylalkyl, alkoxy, aryloxy, amino, silyl, alkenyl, cycloalkenyl, heteroalkenyl, alkynyl, aryl, heteroaryl, acyl, carbonyl, carboxylic acids, ester, nitrile, isonitrile, sulfanyl, sulfinyl, sulfonyl, phosphino, and combinations thereof; and

wherein any two R a , R b , R c , and R d are fused or joined to form a ring; and

wherein at least one of the R a , R b , R c , and R d includes R 1 .

20. The consumer product of claim 19 , wherein the consumer product is selected from the group consisting of a flat panel display, a computer monitor, a medical monitor, a television, a billboard, a light for interior or exterior illumination and/or signaling, a heads-up display, a fully or partially transparent display, a flexible display, a laser printer, a telephone, a cell phone, tablet, a phablet, a personal digital assistant (PDA), a wearable device, a laptop computer, a digital camera, a camcorder, a viewfinder, a micro-display, a 3-D display, a virtual reality or augmented reality display, a vehicle, a large area wall, a theater or stadium screen, and a sign.